dear aspirant, as per my research done on the website of SRMCEM the faculty of ECE branch for b.tech is good. But on frank note of GATE preperation the faculty of a college doesn't play a very important factor(remember that exceptions are there). If you truely want to prepare for GATE examination then you must buy GATE material as it will surely help a lot. Best GATE study material as I would suggest is Made-easy study material for GATE.  

Actually 

It doesn't depend on faculty.

It depends on your preparation. Many colleges don't give gate coaching.

You should  do self study and practice a lot

The faculty of SRM are not too bad but it's your efforts to clear gate exam.

They will clear your doubts .