JEE Main Scores

No, but you won't be able to get a seat in NIT. Moreover, trying for lower NITs with some unknown branches is not worth.
Kindly go for private colleges, universities or try for a year drop.

No. Since the top colleges of Pune take students on the basis of MHTCET, you need to mention those marks if you have given it. Moreover, with the above-mentioned marks in JEE Mains, you'll not be able to get a good private college which stands for a position on a national level.

Below is the link to official cutoff marks for GRIET branch-wise. Kindly make the decision accordingly.
http://www.griet.ac.in/eamcet.html

It depends upon your choice. If you can handle the pressure and study the syllabus with the same dedication that you studied for two years before, then you can take it. Moreover, you need to work very hard as you mentioned you have very less marks in Mains this year.
Also, you can take admissions in private universities, but if you have another chance to prove yourself, go for it.

Hello,
I hope you are doing well. You can check the list of colleges including NITs and IIITs that you can get according to your marks and rank. Use Shiksha JEE college predictor:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=7489993

I would suggest you to directly consult the colleges for admissions through on-campus procedures (management quota is different) as getting a college through online counselling is not possible. Also, try for admissions into private universities who have their entrances too.
Best of luck.

You'll not get any IIIT. But you'll easily get an NIT of lower ranking with mining and similar non - technical branches.
Best of luck.

Your MHTCET marks will not help you to get admissions in Madhya Pradesh. The best colleges in Madhya Pradesh are GSITS, Jabalpur Engineering College, MITS Gwalior, GECU Ujjain, RGPV Bhopal. You'll only be able to get RGPV Bhopal and GECU Ujjain with your marks.

Hello, I hope you are doing well. You can check the list of colleges including NITs and IIITs that you can get according to your marks and rank. Use Shiksha JEE college predictor:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=7489993

Hello, I hope you are doing well.
You can check the list of colleges including NITs and IIITs that you can get according to your marks and rank.
Use Shiksha JEE college predictor:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=7489993