How we can do the following task:
During the running time we can skip the any package or case...?
You can not skip the particular test cases directly in CTS. For that you have to execute the Test Cases manually which you want to execute. Since there are thousands of test cases so there is a short way to execute test cases, use the short package name which is common.
eg. you can use $ start --plan CTS -p android.app
So this will executes all the test cases which starts with name android.app, like
android.app.cts.ActivityGroupTest
android.app.cts.AlarmManagerTest
android.app.cts.AlertDialogTest
android.app.cts.InstrumentationTest
and so on...