Exam

Hello Shivam,
You can get admission for BE in fire and other related courses. JEE Mains is one of the ways to land up in a good college. Even if you haven't given the exam, it is no big deal. You can apply for the colleges with your board exam scores.

You can try for newer IIITs for CS branch.

No, chance if you are from outside of Delhi.

If your parents belong to Army, then there can be some chance.

It is quite difficult to get ECE seat in GVPEC, because your rank is not enough to get admission into this college due to high demand for seats. All the best.

Yes, for sure, you will get it.

Generally, Entrance test of travel and tourism are based on general aptitude, simple mathematics calculation, Grammar and communication and lots of GK about history, architecture, places, tourism, culture. You need to know about the world. You can prepare of your own and for aptitude and mathematics practice, there are thousands of books in the market.

It's not possible for a general category even if you belong to EWS to get admission in NITs with this rank!
You can only go with college predictor tool to know in which colleges you are eligible to apply. https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor.