There are certain criterias that need to be satsfied if you want to get admission into and undergraduate course, namely B-Tech in your case, in Thapar University:

1. 10+2 with 60%marks and 55% for SC/ST

2. At least 20% marks in JEE Main (15% for SC/ST)

OR

1. 10+2 with at least 80% marks (75% for SC/ST) aggregate in Physics, Mathematics and any one of- Chemistry, Biology or Computer Science

2. 15% marks in JEE Main (10% for SC/ST)