if I had got 81.67 percentile then what will be my ews category rank in jee mains

Hello.
Predicting your category rank is quite difficult, but your all India rank can be predicted by using the given formula:
(100- your percentile score)* 869010/100
Hare 869010 is the number of candidate appeared for the January session of exam so by using this formula your approximate AIR Would be: 159,290.
If we consider the number of candidate appeared for the examination would increase to 12,00000 in September session of exam then your approximate AIR would be: 219,960.
If you want to predict colleges then you can go with our college predictor tool through the provided link:

Best of luck.

Hello if you have calculated your marks then please let me know them so that I can give you a predictable rank , it is very difficult to calculate exact rank as it depends on factors like number of students giving the exam and exam difficultly level. So at your percentile from last year cutoff I think you may expect rank between 190- 200k. Your category rank depends on number of students giving Jee mains exam in your category. Hope this will help you.

This should help you