How to get input of VR head movement??!!

My question is how to get VR head movement?!!!

If you have set up your project for VR correctly (follow the VR tutorial) then your main camera will update its transform based on the orientation of the VR headset automatically!

You can get at the main camera using the Camera.main helper property:

// For example...
Camera headsetCamera = Camera.main;
Vector3 headsetForwards = headsetCamera.transform.forwards;

From there you can do whatever you like–it’s a standard transform like on any GameObject.