Hello Anupam,

As per JEE Main Eligibility Criteria 2020 , For NITs, IIITs and CFTIs admissions , the candidates should have obtained a minimum of  75  % aggregate marks or be in the top 20 percentile of their respective boards. For SC/ST category, a minimum of 65% marks required .

JEE Main 2020 B.Arch/B.Planning Admission: Candidates should have passed 10+2 or equivalent exam from a recognized board with a minimum 50% aggregate marks.

NOTE - you can appear for JEE mains exam with any score ,for the examination there is no such kind of percentage criteria but  you are not Eligible  ( below overall 75%)  for Admissions to NITs, IIITs and CFTIs.

Hope IT Helps

All The Best !!