Android Radio Button Not Checked

I am adding three radio buttons in my xml file. each radio button is in separate LinearLayout but same xml. Firstly i don't know how to add them to radiogroup while keeping them in separate LinearLayouts. secondly i wrote the following code to check only one radio button. But this is not working. Please let me know how should i proceed and if there is any better solution. Here is the code.

RadioButton screenof;
RadioButton screenof3;
RadioButton onexit;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.settings);
    screenof = (RadioButton)findViewById(R.id.radioscreenof);
    screenof.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if(!screenof.isChecked())
            {
                screenof.setChecked(true);
                screenof3.setChecked(false);
                onexit.setChecked(false);
            }
        }
    });
    screenof3 = (RadioButton)findViewById(R.id.radioscreenof3);
    screenof3.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if(!screenof3.isChecked())
            {
                screenof3.setChecked(true);
                screenof.setChecked(false);
                onexit.setChecked(false);
            }
        }
    });
    onexit = (RadioButton)findViewById(R.id.radiolockimmediately);
    onexit.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if(!onexit.isChecked())
            {
                screenof3.setChecked(false);
                screenof.setChecked(false);
                onexit.setChecked(true);
            }
        }
    });
}

Here is the xml file

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:layout_weight="1"
    android:background="@color/widgetcolor"
    >

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:layout_margin="1dp"
        android:background="@color/deactiveTexts"
        android:clickable="false"
        android:layout_weight="1"

        >

        <TextView
            android:text="Lock Mode"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textSize="17dp"
            android:layout_weight="1"
            android:textStyle="bold" />
    </LinearLayout>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:layout_margin="1dp"
        android:background="@color/colorAccent"
        android:layout_weight="1"
        android:id="@+id/lockscreenof"

        >

        <TextView
            android:text="Lock apps at screen off"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/textView2"
            android:textSize="17dp"
            android:layout_weight="1"
            android:textStyle="bold" />

        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/radioscreenof"
            android:layout_weight="1"
            android:paddingRight="30dp"
            app:buttonTint="@android:color/holo_green_dark"
            android:elevation="0dp"
            android:duplicateParentState="false"
            android:checked="false"
            />
    </LinearLayout>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:layout_margin="1dp"
        android:background="@color/colorAccent"
        android:layout_weight="1"
        android:id="@+id/lockscreenof3"
        >

        <TextView
            android:text="Lock apps after screen of for 3 minutes"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/textView3"
            android:textSize="17dp"
            android:layout_weight="1"
            android:textStyle="bold" />

        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/radioscreenof3"
            android:layout_weight="1"
            android:paddingRight="30dp"
            app:buttonTint="@android:color/holo_green_dark" />
    </LinearLayout>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:layout_margin="1dp"
        android:background="@color/colorAccent"
        android:layout_weight="1"
        android:id="@+id/lockimmediately"
        >

        <TextView
            android:text="Lock apps immediately upon exit"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/textView1"
            android:textSize="17dp"
            android:layout_weight="1"
            android:textStyle="bold" />

        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/radiolockimmediately"
            android:layout_weight="1"
            android:paddingRight="30dp"
            app:buttonTint="@android:color/holo_green_dark" />
    </LinearLayout>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:layout_margin="1dp"
        android:background="@color/colorAccent"
        android:id="@+id/passonce"
        android:layout_weight="1"
        >

        <TextView
            android:text="Enter password once to unlock all apps"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/textView4"
            android:textSize="17dp"
            android:layout_weight="1"
            android:textStyle="bold" />

        <CheckBox
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/checkpassonce"
            android:layout_weight="1"
            android:paddingRight="30dp"
            app:buttonTint="@android:color/holo_green_dark" />
    </LinearLayout>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:layout_margin="1dp"
        android:background="@color/colorAccent"
        android:id="@+id/displayhint"
        android:layout_weight="1"
        >

        <TextView
            android:text="Display lock mode hint"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/textView5"
            android:textSize="17dp"
            android:layout_weight="1"
            android:textStyle="bold" />

        <CheckBox
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/checkhint"
            android:layout_weight="1"
            android:paddingRight="30dp"
            app:buttonTint="@android:color/holo_green_dark"
            android:checked="false" />
    </LinearLayout>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:layout_margin="1dp"
        android:background="@color/deactiveTexts"
        android:clickable="false"
        android:layout_weight="1"
        >

        <TextView
            android:text="Password"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/textView6"
            android:textSize="17dp"
            android:layout_weight="1"
            android:textStyle="bold" />
    </LinearLayout>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:layout_margin="1dp"
        android:background="@color/colorAccent"
        android:clickable="true"
        android:id="@+id/changepass"
        android:layout_weight="1"
        >

        <TextView
            android:text="Change password"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textSize="17dp"
            android:layout_weight="1"
            android:textStyle="bold" />
    </LinearLayout>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:layout_margin="1dp"
        android:background="@color/colorAccent"
        android:id="@+id/invisiblepattern"
        android:layout_weight="1"
        >

        <TextView
            android:text="Invisible Pattern"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textSize="17dp"
            android:layout_weight="1"
            android:textStyle="bold" />

        <CheckBox
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/checkpatinvisible"
            android:layout_weight="1"
            android:paddingRight="30dp"
            app:buttonTint="@android:color/holo_green_dark" />
    </LinearLayout>

</LinearLayout>

I edited the code and pasted your code but when i ran the code there were unexpected results. I put the print statements and here is what it printed. I clicked on the buttons top - down once.

Case 1
Case 1
Case 2
Case 2
Case 1
Case 2
Case 3

You can do this by implementing OnCheckedChangeListener

try below code it will work for you-

screenof= (RadioButton) findViewById(R.id.radioscreenof);
screenof.setOnCheckedChangeListener(quest1);
screenof3= (RadioButton) findViewById(R.id.radioscreenof3);
screenof3.setOnCheckedChangeListener(quest1);
onExit= (RadioButton) findViewById(R.id.radiolockimmediately);
onExit.setOnCheckedChangeListener(quest1);

CompoundButton.OnCheckedChangeListener quest1 = new CompoundButton.OnCheckedChangeListener() {

    @Override
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
        switch (buttonView.getId()) {
            case R.id.radioscreenof:
                radioscreenof.setChecked(true);
                radioscreenof3.setChecked(false);
                onnExit.setChecked(false);
                break;

            case R.id.radioscreenof3:
                radioscreenof.setChecked(false);
                radioscreenof3.setChecked(true);
                onnExit.setChecked(false);
                break;
            case R.id.onExit:
                radioscreenof.setChecked(false);
                radioscreenof3.setChecked(false);
                onExit.setChecked(true);              
        }
    }
};