hi,

see you can not change your btech college based on your jee main or 12th score, however if both of the college comes under same university migration might be possible, another thing you can again sit for counselling in jee main , then it you have got a much better college then the present college you can again take admission from first year , but mean while your 1 year will be loss, and again you need to study from first year, but at this percentile less chances for nits, right now jee main april session registration has again open, if you did not applied before you can still fill the application  form, from May 19 to 24, 2020

however thaper institute of technology has admission process for btech students who are in first year and want to join thaper from second year. you need to appear in the entrance test conducts by thaper to avail the admission process.