NIT

For NIT college, you have to score around 200 marks in JEE Mains paper. But, for IIT you will have to qualify JEE Advanced exam.

It's perfectly fine if the college overall ranking is good plus placements, faculty etc. Hence, location of the college is not an issue if the college reviews are good.

Hello, Getting a seat in a particular NIT or for that matter any NIT is a function of multiple dynamic factors. But your percentile appears to be quite good. I am attaching a link that will predict college for you. I hope you have applied to appear for JEE Mains once again to improve your percentile. https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor
Best wishes to you.

I think you need about 96 for NIT. Try again in April brother.

If you get less than 75% in class 12th, you are not eligible for IIT. But, you can get NIT with that percentile.

Being an OBC student aiming for NIT Patna. I can say, you hold a chance of getting a seat into it.
Good luck
All the best

The final AIR will be declared after April 2019 considering the best score out of the two JEE Main attempts for all the applicants, hence based on current percentile we cannot predict whether you will qualify for which NIT or government institution. Wait for the final AIR declaration
Details:
https://www.shiksha.com/b-tech/articles/how-to-calculate-jee-main-rank-from-percentile-blogId-19953.

Yes, IIT Allahabad is still having that much potential, you should give preference to it. Although it will require you to score a really good score to get admitted as compared to NIT's. Placements totally depends on your attitude and your knowledge in the domain. So, work on that and you need not to worry about the placements.
All the best!

Yes, you can. But, I don't think you will get the top NIT. The newer NITs are the chances and branches other than Mechanical CSE IT ECE Civil in good NITs, you can get. Though nothing can be surely said.

Mining in NIT RKL is good. You can even opt for chemical or mining. I would rather suggest mining seeing it's opportunities. With 97.62, you stand a chance of getting into one.