you have taken one of the best option in your consideration..here  you go.

For BTech admissions, 70% of the total seats are filled on the basis of the JEE Mains rank and rest 30% based on class 12 merit followed by counselling.

you can also opt for BTech Integrated there is little hope that you may get

but with your score in JEE mains there really no chance to get in SASTRA in any branch .go with your marks in 12th std.

you are looking for CSE but as my suggestion also go for information and communication technology..if you wish that too will have similar study throughout the course.

lets always hope for the best and do what we can and that's it

good luck..!!,hope for the best.

Hey,

Your 12th score is good and you will be eligible for most of the college options. Your jee mains percentile is very low for which your rank will be over 10-20 lakh.

There is low change to get sastra university through general rank. If you have reservation category then there is some hope to get atleast in non technical branch.

Better to apply for SU and along with it apply for your state domicile government college and 1-2 private college options for security.

It would be better to look out for your final rank them decide for college list.

Hope it helps!