Hello

First of all there's no percentage barrier to be eligible for JEE mains

For example,

Eligibility criteria says that to be eligible  for JEE mains 2020 for BE or Btech you just must be either appearing for 12th board exam in 2020 or should have passed it in 2019 or 2018 with Physics,  mathematical  and anyone of Chemistry or Biology or Biotechnology or Technical Vocational Subject.

But yes , there was % barrier for jee advanced according to which to be eligible  one needed at least  75% marks in aggregate in class 12 if belong to general or obc category or at least  65% marks if belongs to SC/ST or  must be in the top 20 percentile in  class 12 examination but now this has been scrapped off and now there's no % barrier for jee advanced

Thank you