Kartik, I believe you mean that your percentile is 82 and not your percentage. Now you can calculate your approximate rank for JEE Mains using your percentile through the following formula:

(100-your total percentile) x 869010/100

So with 82 percentile, your rank would be around 156421.

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

Hence your expected rank in this case would be around 216000.

Now the cutoff rank for CSE at Thapar University, Patiala ranges around 20000- 25000. With your rank, it won't be possible to get a seat at Thapar.

I would suggest you to sit for the April session and give your best in that exam so that your chance of getting your choice of college increases. Solve the previous years' papers, brush up your concepts and revise thoroughly.

Although you can 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.