To work with ConstraintLayout, you need Android Studio Version 2.2 or newer and have at least version 32 (or higher) of Android Support Repository.

1. Add the Constraint Layout library as a dependency in your build.gradle file:

dependencies {
   compile 'com.android.support.constraint:constraint-layout:1.0.2'
}

1. Sync project

To add a new constraint layout to your project:

1. Right-click on your module’s layout directory, then click New > XML > Layout XML.
2. Enter a name for the layout and enter "android.support.constraint.ConstraintLayout" for the Root Tag.
3. Click Finish.

Otherwise just add in a layout file:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="<http://schemas.android.com/apk/res/android>"
    xmlns:app="<http://schemas.android.com/apk/res-auto>"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

</android.support.constraint.ConstraintLayout>