Thapar University is an excellent choice for CSE, with placements much exceeding expectations, but comparing it to IITs is simply not justified. IITs are India's premier universities, and Thapar is nowhere in comparison.
When it comes to NITs, Thapar is superior to the majority of them, with the exception of a few You can check the NIRF rankings to confirm the same. Thapar will also provide you with significantly greater exposure than most NITs.
It's up to you to make your decision. I dropped out of IITs because I couldn't afford to earn decent JEE advance scores. IITs are the finest place to be if you are a confident and hardworking young man.