NIT

Yes, you can do that.

You can join NIT. If you are confident, then you can prepare it along with your college.

No, regular candidates should possess a valid score in the Common Admissions Test (CAT) conducted by the Indian Institutes of Management. IIT graduates, who obtain a CGPA of 8 and above on 10 are exempted from CAT score. Their shortlisting will be based on a composite score with due weights to applicant CAT score, past academic performance, industry experience and gender.

For CBSE, its 75% and for other state boards, it varies.

In order to get in IITs, you need to qualify in JEE (Mains) & then JEE (Advance). Start preparing now. It's tough but not impossible.
All the best.

Hi Harsh,
I believe your query has been answered previously by Vikram Soni. You must have an overall score of 75%. Please also refer to the answer he provided and follow the advice.

Yes, it do accept SAT score, for other colleges accepting SAT score, check out the link below:
https://www.shiksha.com/top-engineering-colleges-in-india-accepting-sat-score-rankingpage-44-2-0-0-418

NIT Jalandhar is a better option in comparison to Thapar university in term of Return On Investment for doing B.Tech CSE.

Hello Rahul,
Presently NIT, Jalandhar is not considered a top college. Due to this, opening as well as closing ranks are quite relaxed. I feel that the minimum marks would be 200+. But may I ask why are you asking the minimum marks? You should dream of getting into IIT and that too of your choice. Once you have a dream, you should surely work towards it.
Best wishes.

Dear,
To qualify in NIT, a student should have 75% in class 12th for general students and for SC/ST/OBC should have 65% in class 12th with subject of (physics, chemistry, mathematics and English).
All the best!