I have got 83 percentile in jee main 2020 category OBC does I get any NIT with mechanical branch

Hello..
It is quite difficult to predict your actual rank so your approximate rank at 83 percentile would be147, 731 remember it is when if we don't consider category wise rank. Now using this rank you can use previous year cut off list of JEE mains which can definitely help you to find your chances of getting admission in NIT with your desired branch.
Link of previous year cutoff list is given below:
https://engineering.careers360.com/articles/jee-main-cutoff
Now for knowing more colleges you can also use our college predictor tool from the below link:

Best of luck.