JEE Main

Yes you can easily get admission in Birla Institute of Technology and Science Pilani campus in chemical engineering but in the last round of the counseling.

You can fill any JEE Main roll no. Because both are related to your profile. But, it is suggested that you have to fill the roll no. Belongs to high NTA percentile/ Marks.

The minimum expected NTA percentile is 89.5, required to be qualified for JEE Advanced 2019 exam.

Hi,
You can refer the following link for the answer key and marks awarded. https://www.shiksha.com/b-tech/articles/jee-main-2019-paper-1-final-answer-keys-out-full-marks-awarded-for-22-wrong-questions-blogId-19971.

A OBC candidate is as good as OC candidate if he or she doesn't fall in NCL (Non creamy layer)
So, if I assume you a NCL candidate, then about 120 is enough to get admission in any of the NITs.

Yes.
There may be chances of getting an admission in any NITs like NIT Silchar or NIT Warangal, NIT Surat, etc., according to your JEE Mains percentile.

Hi, as far integrated course is concerned you need to check the placement records and infrastructure provision in that college. In case of JNU Delhi, it is the first batch of integrated course in 2018 whereas in University of hyderabad the placement record is good.
You can refer to the following links for college reviews by the students themselves:
1. https://www.shiksha.com/b-tech/course/integrated-b-tech-m-tech-in-computer-science-and-engineering-jawaharlal-nehru-university-mehrauli-Delhi-329481
2. https://www.shiksha.com/b-tech/course/b-tech-m-tech-in-computer-sciences-university-of-hyderabad-gachibowli-329529
Good luck!

Not Possible. Why?
1. Thyagaraja college would not give admission on JEE Mains marks.
2. They give admission on TNEA cut off marks.
3. Hope you know how to calculate that.
4. Hurry up. You need fill form separately for that.