Hello aspirant, greetings to you. In order to convert you percentile into marks, you can use the link given below,
https://engineering.careers360.com/articles/jee-main-marks-vs-percentile
For calculating the rank, you can fill uo the information in the link given below,
https://engineering.careers360.com/articles/jee-main-rank-predictor
I hope this helps you with your query.
All the best!
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