To get into B.Tech in Cyber Security at IIT Gandhinagar (or similar top IITs) with OBC-NCL category, your JEE Main percentile should ideally be above 90. For top-tier colleges, the closing rank for OBC-NCL students usually falls between 10,000 and 20,000, depending on the competition and year. In terms of percentile, aiming for 90-95% would give you a competitive chance. You should also check JoSAA cutoffs after JEE Main results to know more precise details.