NIT

You will be asked during counseling about your extra co-curricular activity, then you can mention in them.

Congratulations for good marks. For better answer I have to know your category. You can check it on the college predictor in siksha app.

Go for NIT because they provide more facility in term of campus placements and other activities.

You can visit this link:
https://www.shiksha.com/college-predictor

You can visit this link:
https://www.shiksha.com/college-predictor

Check what colleges you can get into, use the link below:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=7489993

NITs are centrally funded institutes and offer you better technical environment with some good laboratories and highly experienced teachers.

Yes , you are very much eligible as there are many private colleges. Our college offers B.E courses in CSE, ECE, EEE, ME, ISE & Civil. For further details, kindly look into our college website www.citech.edu.in. Thank you.

Click on the link for more details:-https://www.shiksha.com/b-tech/ranking/top-engineering-colleges-in-india-accepting-jee-mains/44-2-0-0-6244

JEE Mains and you have to secure above 200 marks to get good NITs or IIITs. You have to take PCM in 12th and must clear the same with at least 75% to appear for IIT JEE. If you score less than 75% then you cant appear for JEE Mains. So, also reappear for 12th to appear for JEE Mains.