NIT

Hello Asif, the exam conducting body for JEE Mains is national testing agency. They declare the results and also announce cutoffs in terms of percentiles for different categories of students. Those who have scored better than this percentile only are allowed to appear for JEE Advanced which is the entrance test for getting admission into any of the IIT. Every year this ranking or rather percentile will keep changing which is the determining factor for eligibility to apply for admission in NIT as well as appearing for JEE Advanced. On the same lines the agency conducting JEE Advanced also announces cutoffs and those who have scored more than the cutoff can only seek admission in IIT. You will get a very detailed information if you visit the website of an NTA and of the IIT. Best wishes to you.