Scroll two or more List views in QML

I need to scroll two or more list view at once using a single scrollBar. Initially, i used Column inside a Flickable but scroll was not happening as expected. Later, I used ListView and even that was not scrolling correctly.

So how to scroll a listview/layout content item with a scroll bar? Should I use ScrollView or Flickable or something else?

You could just use a Flickable with your Columns. I don't know how your Columns are laid out horizontally but if they are inside a Row it's pretty straightforward:

import QtQuick 2.7
import QtQuick.Controls 2.0

ApplicationWindow {
    visible: true
    width: 640
    height: 480
    title: qsTr("Multi Column")

    Flickable {
        anchors.fill: parent
        contentWidth: row.implicitWidth
        contentHeight: row.implicitHeight
        Row {
            id: row
            Column {
                spacing: 5
                Repeater {
                    model: 20
                    delegate: Rectangle {
                        width: 50
                        height: 50
                        color: "red"
                        Text {
                            anchors.centerIn: parent
                            text: index
                        }
                    }
                }
            }
            Column {
                spacing: 5
                Repeater {
                    model: 30
                    delegate: Rectangle {
                        width: 50
                        height: 50
                        color: "cyan"
                        Text {
                            anchors.centerIn: parent
                            text: index
                        }
                    }
                }
            }
        }
        ScrollBar.vertical: ScrollBar { }
    }
}

Even if they are not in a Row you could do :
contentHeight: Math.max(column1.height, column2.height, ...)

Demonstration :