Hello Rakesh,
For admission in NIT's/IIIT's/GFTI's the minimum requirement is you should have 75% marks in your board exams, or you should be in the top 20 percentile.This is for general/OBC category.
For SC/ST 65% marks is sufficient.
For more details,please do find the below link.
https://engineering.careers360.com/articles/jee-main-eligibility-criteria
All the best!!!
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