Hii,

AIR 400 in the GATE exam will get you in most of the IITs.

As to get into IISC Bangalore or IIT BOMBAY for M.Tech requires around AIR 100 and similarly it varies from College to College.

The GATE scorecard is valid for three years

Every PSU is having their individual cutoff of Gate.

Below table gives you an overview of NTPC GATE recruitment branch wise of the year 2018 and 2017 .

For more information about the GATE cutoff please check out the link mentioned below

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

Hope this will help you,

All the very best!!