Colleges in West Bengal

Yes, if you will get more than 8.5 GPA, then you can.

It is in the month of June just look for the respective website from where you have to get admission.
If you have any query do let me know in the comments down below.
All the best.

There are possibility for you to get admission in some NITs. To know in which NIT you are eligible to apply. Use the college predictor tool:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor.

It depends on how the university processes international student's admission. Each university would have an intake period and you are applying for a particular intake. It would depend on how fast the university processes your application and your visa process gets cleared. It is better to contact the university directly, especially if the university has an international student's coordinator. They would be able to give you clear timeline.

Hi,
First of all congratulations, with 122/200 marks in NATA 2019 exams, 97.11 percentile in JEE Mains Paper 2 exam and 75% score in your class 12th, you can surely secure admission in Jadavpur University. The forms for admission are available on WB exams regional counseling authority website.