CBSE 12th

You don't need to give CET if you're joining B.Sc biotechnology.

Yes u will get a seat but u need to submit ur certificate s

Yes, you can definitely apply for NIT Trichy. Guessing on the mark is bit hard because rank varies from year to year. According to the previous records, you can apply.

Hello Devanshi,
Hotel management is a professional course, which allows students from every streams to take admission, as you will be thought everything from the beginning. Hence, you could do your class 12th from CBSE in commerce stream.
All the best.

Unfortunately, your exam results are not that high, as the merit lists attract these days. I insist that this is only your exam result, not your life or career result. You cannot be defined by the numbers or percentile. Still, this pits a limit to the chances to get into the University colleges if there is no other weightage attached to your candidature like reservation. You may explore the option of small buy good colleges in the country. Even the private universities can be good option around you.

Hope so, but you have to wait, till the 3rd merit list.

Yes, of course you need to submit your class 10th, inter/+2 and degree mark sheet at the time of your recruitment.

You won't get admission in NIT's or IIT's. You can get admission in general private institutes, just know the nearby private institutes near you locality.

Well, you should decide it by your own. If you are confident that you will clear the JEE next year, then only you should drop. Otherwise, don't waste your time and get admission in engineering college. There are so many private college, which are also providing best education and placements as well. So, no need to be worry about getting IITs or NITs. All the best.