Could we remotely Delete Office365 users from Provider-Hosted App programatically with C# ? Any suggestions please.
This is actually a question about AD. Although I do not know the exact API, what you are looking for is how to do user maintenance in WAAD. MSoft just released a bunch of new O365 Apis and I am sure WAAD apis were included.
Once you find and test that Api, you should be able to call it from a SP Provider-Hosted app (assuming a credential with appropriate rights.