Hello Aspirant

All most all of the IIT give admission to students on the basis of gate score.

You can get into IIT direct if you have more than 8.0 CGPA and you will have a written test as well as a personal interview.

In the written test you will be asked question related to your branch same as that of gate.Hence it is better to prepare for GATE

But there are three Universities  or IIIT that have their own examination for MTECH and they are as follows

1. IIIT hyderabad :PGEE
2. IIIT Delhi :IIIT Delhi Mtech entrance exam
3. IIIT Bhubaneshwar : IIIT Bhubeshwar Mtech entrance exam.

Regards!