Dear Aspirant,

In this time of uncertainty due to the COVID19 pandemic the NTA and the IIT's have together decided to relax the minimum 75% criteria for JEE 2020.Thus the JEE applicant should only have passed the examination and he can participate in JOSSA counselling.So you should not worry about the top 20 percentile and work hard to achieve a good rank in JEE advanced.All my best wishes to you.May you get admitted in your desired college.

You can also use the college predictor as follows-

https://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer