Hi @Chimni
Welcome to the community!
Video calls are not a part of the calling function in the Xperia devices. You can't make video calls using the native phone app, or via an operator. However, you can download and use a third party application. The prerequisite is that your counterpart uses the same application.
However, we cannot guarantee the performance of any third-party applications. Should you have any functionality issues with a third party applications make sure to get in contact with the developers of the particular app you are using as they should be able to assist.
Also, you can use the preinstalled Google Hangouts application to make video calls, so this is also an option.
Good luck 
0online
1898592posts