Dear Aspirant,

According to previous year data and this year's  paper analysis

50-55 marks may acquire a percentile of 80 or 80+.

Here is a detailed analysis of JEE Mains 2021 Marks VS Rank VS Percentile   :

https://engineering.careers360.com/articles/jee-main-marks-vs-percentile

https://engineering.careers360.com/articles/jee-main-marks-vs-percentile#JEE-Main-Marks-Vs-Percentile-Vs-Rank

Also check -

JEE Mains Rank/Percentile Predictor:

JEE Mains College Predictor tool:

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

This college predictor tool gives prediction of colleges based on your score  with various factors such as entrance exam,location of college, branch...etc.