How much percentile should I need to get in jeemain to get seat in any of the NITS for INSTRUMENTATION AND CONTROL ENGINEERING?(I am SC candidate.)

Hello,
The cutoff will vary from programme to programme and institute to institute. Various factors like the difficulty level ofJEE mainsexam, number of candidates applied in NITs, total number of seats, etc will be considered while determining the cutoffs.
You can get an idea from the previous year cutoff ranks for various NITs for Instrumentation engineering from this link..
https://www.google.com/amp/s/engineering.careers360.com/articles/nits-cutoff-for-btech-electronics-and-instrumentation-engineering
Hope it helps