hi,

see jee main exam is a all india level exam for engineering admission in nits, iits, state and centralized colleges and universities. counselling is based on jee  main score mainly and it differs year to year. till now jee main april session exam is yet to held and if number of participants increased this time it will have effect on current percentile. however for nits and iits you need to secure 75% marks (general and obc) in 12th exam , for sc/st qualifying marks criteria for nits and iits is 65%.