Which institute I may get with 84.4% in class 12th and score of 82 JEE Mains?

Nishant you have not specified your state. Your tentative rank is going to be above 75000. So, the colleges that you are going to get on the basis this rank are from all over India, please check the link below https://www.shiksha.com/jee-mains-college-predictor You can also try for direct admission

Dear Nishant, Keeping in mind this year JEE (Main) paper analysis, last year cut offs and only your JEE Main marks (boards not included), you may expect the below colleges Bhagwant University, Ajmer Vivekananda Global University, Jaipur Gurukula Kangri Vishwavidyalaya, Haridwar Lingaya's Universit

At this score it is difficult but you are reserved category candidate you can try for this some time there are not so much students find in this category then you can get chance at that point