Helo Shreya
This is for IIT mumabi and  please fo mention for which college your are asking for.

MTech TA -
MicroElectronics (AIR upto 30)/
Electronic Systems (AIR upto 65)/
Communications (AIR upto 80)/
Power Electronics and Power Systems (AIR upto 100)/
Control and Computing (AIR upto 220)
MTech RA-
In 2013 ranks up to 9001000 were called in for test. The final selection is based on GATE score+ Test Performance+ Interview Performance. So, there were people with 200 AIR who did not get shortlisted and people with 900 AIR who got selected in MicroElectronics.