See GATE is a national level examination and the score is accepted by most of the top colleges. So if you wish to get into IIT's/NIT's and other top institutes then going for the GATE can be a great choice. Apart from them, most of the other college also requires GATE score. Now there are some colleges which offers the admission to the course of MTech without GATE, the name of those institutes are provided below:

1. IIIT Hyderabad PGEE-Test
2. IIIT Delhi- Test
3. IIIT Bhubaneswar- Test
4. BITS Pilani HD -Test
5. VITMEE -  for Vellore Institute of Technology
6. IPUCET , Delhi
7. SRMGEET
8. AP PGECET
9. VITMEE
10. JNU CEE M.TECH
11. CUCET Engineering

For more information regarding the MTech as a career consider the link below:

https://www.careers360.com/courses/m-tech-master-of-technology

I hope this helps. Wish you a great day!