Eswar, while it is difficult to estimate your EWS category rank using percentile, you can calculate your approximate rank in the Common Rank List for JEE Mains through the following formula:

(100-your total percentile) x 869010/100

Also, if the number of students increases to 12 lakh in the April session, the formula for rank calculation would change to:

(100-your total percentile) x 1200000/100

While it is difficult to predict this year's qualifying score for JEE Advanced, we can use the previous years' cutoff to estimate this year's qualifying score. In 2019, the cutoff for JEE Advanced was 78.2174869 NTA score. So a score of 76-78 in JEE Mains 2020 would be decent enough to qualify for JEE Advanced.

You can also go through our college predictor to check which colleges you are eligible for through your JEE Mains score. The link for the college predictor is:

All the best.