Hello Aspirant

Use this formula to predict your rank:
Rank Formula = (100 - your total score) X 874469 /100.

But this rank differentiate from official Results which were released on the month of April.

By rank the cutoff for Nits is decided.i will provide link from career 360 for previous years cutoff for Nits once you compare the cut-off you will get an idea:

https://www.google.com/amp/s/engineering.careers360.com/articles/jee-main-cutoff-for-top-nits/amp

If you have any questions further let me know.

Thank you!!!!