Hello Uday,

Yes obviously you can join IIT's on the basis of your score in GATE. 

If you want to check cut off of IITs, you can refer:

https://engineering.careers360.com/articles/gate-cutoff-for-iits/amp

Good luck

Hii aspirant..

Yes IIT institutes take admission in Mtech program through GATE exam. Out of all the IIT some IIT take a personal interview after the GATE exam for the students who have qualified the cutoff. While there are other items which take admission solely on the basis of GATE exam. Thus if you score well you can get admission in IIT for MTech easily.

Hope it helps. 

Best of luck