IIT

No, IITs and NITs don't accept UPSEE, but you should go for. LPU or Amity. They accept UPSEE scores.

IITs have a great faculty and you can definitely pursue your masters in aeronautical engineering from IITs. But, if you can afford studying in abroad, you can also go for it.

First of all if you are general then you are not eligible for IITs NITs or GFTIs as they need 75% marks minimum but if you are ST, SC then there is a chance if your JEE main marks is good.
then you get scholarship on your fee structure by IIT.

Yes, you can go for a free ship scholarship under economic criteria in any institute in India.

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 is also given there. Download and go to a doctor take a fitness certificate.

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.