CBSE 10th

You can take a computer course which is for 1 year and start your work as a teacher in the academy itself.

If you are in doubt, then don't choose Science. For Science, you need your full dedication and make up your mind accordingly. Students who choose Science are 100% sure in their ability and have proper goals for their career. If you don't think you can handle Science then don't choose it. Go for commerce or Humanities in your 12th.

Yes, you are eligible to appear for entrance exam of IIFT.
The minimum percentage required to fill up the application form is 50%.

If you score really good in CAT and other exams like NMAT, MAT, etc., then maybe you will get a call from a decent college and if GD and PI go well, maybe you will get admission. But there is a very thin chance.

Yes, you can apply for the animation course and the fee would depend on the institution from which you will pursue an animation course.
Good luck.

You can admission in this college if you get good marks in the entrance exam and also in class 12th.
Good luck.

Just submit a self-declaration stating a suitable and valid reason for the gap and you will be fine.

You will need 99+ percentile in CAT to get FMS. FMS is usually a top choice just after IIMs. Hence you need to score higher.

More than 99.5 percentile in CAT is required to get the admission in IIM for MBA. You have a good score in 10th and 12th.

Admission in this university is based on the result of the ATMA exam:
https://www.shiksha.com/mba/course/master-of-business-administration-gauhati-university-Guwahati-71254.