Hey there
75% is a benchmark mostly for CBSE students but since State board students get less marks so for them top 20 percentile is there and thus if you'll be top 20 percentile as per your category then you'll be automatically eligible
Check the link
https://www.google.com/url?sa=t&source=web&rct=j&url=https://engineering.careers360.com/articles/jee-advanced-eligibility-criteria/amp&ved=2ahUKEwjylayt5rnpAhVTIbcAHV58Dv0QFjALegQICBAB&usg=AOvVaw01aKmN36HHlgNxEQPk11Z4&cf=1&cshid=1589680605528
Good luck
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile