Colleges in Tiruchirappalli

Use the links mentioned below
https://www.resonance.ac.in/jee-main-answer-key-solutions/jee-main-2016-rank-predictor.php
https://www.shiksha.com/jee-mains-college-predictor

Yes, you will get a seat. Apply for NITT ECE too for back up. You will need a OC rank of 1500, but OBC rank varies widely.

I've heard that IIITH is very good for CSE. But facilities in NITT for CSE along with placements are good.

I don't think that mains score is enough to secure a seat. You will need around 180-200 for that.

Dear Nijith,
Both the institutes mentioned by you are equally good and thus it will be very difficult to tell which one will be the best option. However, we can help you with the parameters that you can keep in mind while choosing an institute among them. You can consider the below parameters :
1) Faculty,
2) Affiliation / Recognition
3) Course Material,
4) Quality Education,
5) Fees
6) Infrastructure
7) Success Rate.
8) Placement
9) Top recruiting companies.
Also, if possible go through the alumni speak section to get an idea what the alumni thinks about the institute.
Hope this information helps. Please feel free to revert.
Wish you luck.

It is difficult to get CSE or ECE in NIT Trichy. But you can try for EEE or Mech. But cannot be too sure either, but is possible. Your scores are in the border regions to get admit. You will get a seat if your boards score was above 92%.

It depends on your institute. Some institutes don't have internal sliding. Some do have it and Its either at the beginning of first year or the end of it. A notice will be given to you by your college. You will have to fill up a form and depending on the vacancy and your grades you might or might not get a change of branch.

NIT-Trichy is one of the premiere institutes of India. If you ask specifically about chemical engineering, it is one of the best. Senior faculties are really good. Core concepts of chemical engineering are taught professionally. Placements for chemical engineering are 100% and average CTC is approximately Rs.6 LPA.(For core companies).