According to some reports, T-Mobile will support RCS in "Q2 of 2018" - anywhere between April 1st and June 30th. I do not use T-Mobile so I do not know if they already support RCS. Also, did Huawei update their messaging app to support RCS? To be sure your phone supports RCS software-wise, you can install the Android Messages app and Carrier Services.
The phone itself has nothing to do with RCS as that's entitely software side. The modern phones just need an app that supports RCS like Android Messenger, and that the carrier supports it.