Hello,

Yes you can do your M.Tech in Computer Science Engineering after B.Tech in IT. But for this you need to appear for the GATE exam since most of the M.Tech admission will be done as per marks in GATE exam while some institutes conduct their own entrance test or interview for admissions.

Below link will provide you with some of the best colleges for M.TEch in CSE in India. You will also get details of each college which includes the entrance exam accepted by them:

https://engineering.careers360.com/colleges/list-of-me-mtech-in-computer-science-engineering-colleges-in-india

Good Luck