Yes, you can get CSE at Thapar University easily even if you don’t hail from Punjab. The reason is even with low marks students can get some other branch and then appear for the December Test to upgrade their branch to CSE. You need to be among the top 20 students to upgrade your branch to CSE. Another option is to make sure you have a 9.7 CGPA or higher in the first year. This will increase your chances of upgrading your branch to CSE.
The subjects taught in the first to students of all branches are the same so you won’t lag behind in your branch. Also, the pattern and syllabus of the December test are exactly like JEE Mains so you don’t have to worry about preparing for it separately.
Hope this helped you!