Hello aspirant

You can check this following link for the previous years gate cutoffs for nits, using this link you can predict the trend and the minimum marks required to be eligible for the same.

https://www.google.com/amp/s/engineering.careers360.com/articles/gate-cutoff-for-nits/amp

As per the data for 2019, the cutoff marks for instrumentation for general category was 31.9, for obc 28.7 and for sc/st 21.3

Hopefully this helps