IIT

Hello Ship,
No, you cannot take admission in any IIT's or IIEST via WBJEE, via WBJEE you can get state funded government colleges of West Bengal like Jadavpur university, Kalyani, etc.

Please read the JoSAA business rules. You have to take all the original certificates of your academic and caste. There are some certificate formats available at the JoSAA notification PDF file in the end. That you have to take the printout and take necessary action given there. Plus medical format i

The minimum 45% marks require in +2 for admission in engineering.

If you want to good job then improve your communication skills first and as per your profile, operations or production management is the best suitable for you.

If you want to get an admission in IIT, you should clear JEE Mains. None of the IITs offer admission based on 10+2 score. So, don't go for improvement exam.

It all depends on your interest. Electrical is a core branch, so choose wisely. I would suggest going for electrical in IIT Dhanbad as placements are good in electrical. If the branch would have been same, then IIT BHU would be the choice.

You are definitely eligible. A few seats are available in IIT for foreign students.

Hello Tripti,
As per your rank in JEE Mains and Advanced, your chances are slim to get any NITs or IIT's, however, check here for more insights.
JEE Mains
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor.
JEE Advanced.
https://www.resonance.ac.in/reso/news/jee-advanced-branch-allotmen

Hello Rohan,
As per your rank your chances are nil to get any IITs if you belong to general category,however check here to be more clear:
https://www.resonance.ac.in/reso/news/jee-advanced-branch-allotment.aspx

Definitely, NIT Nagpur. If you are looking for good faculty members and placements.