Akshay your query is incomplete. What actually you want to know?

If you are asking that to appear in JEE Advanced exam you need to clear JEE Mains exam or not then yes you need to pass of the minimum marks cut-off which is given separately for each category in order to be eligible for sitting in JEE Advanced examination.

And no matter how many marks you have got you can apply in different private engineering colleges and also sit in the seat allotment session of NITs but you will get a seat in any of the colleges only if your rank is good enough to clear the cut-off of that college.