SMEAT

Sastra CSE branch will have more competition. Maybe you won't get CSE seat. If you are more college preferable and in 1at year all people will read the same. So if you are confident that you will get 9 GPA then you can get your CSE branch then. If upto now your are adjustable with any branch you can apply.

There will be a very less chance to get ECE seat in sastra Thanjavur. We have kumbakonam branch of sastra there you can get your ECE seat. Apply first and then they will give ranking based on that they will give instructions.

Yes, you have a chance to get bioinfo. Maybe if you won't get in 1at counselling try for the next.

Sastra won't considers any EWS type. They will consider AIR ranks only. Maybe it's difficult to get a CSE seat with your score. If you are more preferable to college and don't consider any branch in first year. If you avail 9 GPA in 1at year. You can change your branch from anything to CSE.

No chance , your chances are very low not even in trichy but in all NIT'S.

Your expected JEE Main AIR is about 139178, Which is very good enough for getting admission in Amrita Vishwa Vidyapeetham in desired engineering branch.

May be you can expect M.Tech. But don't be sure about that. Wait upto last counselling.