IIT

You cannot get seats in IIT on the basis of Jee Mains rank. You have to clear JEE Advanced to get IIT. Seats in NITs are given on the basis of JEE Mains score, but your rank is very low, your chances are less of getting NITs, but you can get colleges of your state. Try JEE college predictor to get more information and insight about college which you can get on the basis of your rank:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=4067795

If you think you can manage the preparations without losing concentration, then go for it. Your class 12th marks suggest that you have the calibre to score 100+ marks in JEE. So, if you can prepare without being frustrated, go for it.

No, you don't get admission in NIT or IIT through JCECE. You have to crack JEE Mains for NIT and JEE Mains and advance for IIT.

You can check here. Use Shiksha JEE College Predictorhttps://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=cconnect&utm_medium=CR_JEECP&utm_campaign=7489993.

You need to crack JEE for that.

You may get a good college. So, you should try for a good college as your rank is not that good but you can get an autonomous college.

If your concepts are clear of each and every topic, you would easily crack NEST exam without any problem.

I think you have bad Marks in JEE, then you will also not be getting any Government Colleges. You should try for other private colleges. Try this Shiksha college predictor to get the colleges on the basis of your JEE Mains rank. Wish you best of luck. https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=cconnect&utm_medium=CR_JEECP&utm_campaign=6540165.

Your chances are vary rare of getting NITs. But, you can get colleges of your state May be government colleges. Try JEE college predictor to get more information and insight about college which you can get on the basis of your rank-
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=4067795.

Your chances are vary rare of getting NITs. But, you can get colleges of your state May be government colleges. Try JEE college predictor to get more information and insight about college which you can get on the basis of your rank-
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=4067795.