Dear Aspirant,

See there is no Percentile score in JEE Advanced , NTA provides percentile score for JEE Mains .

You can detailed analysis of Marks VS Percentile VS Rank of JEE Mains 2021 here in these links:

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

According to these 91-100 marks would correspond to 95 percentile .

JEE Mains cutoff percentile & Expected  Marks to qualify for JEE Advanced-

https://engineering.careers360.com/articles/jee-main-cutoff

https://engineering.careers360.com/articles/jee-main-cutoff#Expected-Qualifying-JEE-Main-Cutoff-2021-Marks

Due to changing trends of JEE Advanced every year its quite difficult to predict JEE Advanced Marks VS Rank

Once JEE Advanced 2021 is done you can find articles about analysis  on Careers360 website.

JEE Mains College Predictor-

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

JEE Advanced College predictor-