Karnataka

IIM-B will be the best option for you. Other options include Jain University and IIM-A (E-PGP).

It is a good institute, but there are many other good colleges available to pursue BCA.

You may refer to the following link for the list of top B.Tech CSE colleges in Bangalore:
https://www.shiksha.com/b-tech/ranking/top-computer-science-engineering-colleges-in-bangalore/46-2-0-278-0.
The best engineering colleges in Bangalore for B.Tech in CSE are:
R.V. College of Engineering
Rashtreeya Sikshana Samithi Trust, Mysore Road Bangalore. The college is affiliated to Visvesvaraya Technological University. The admission is based on KCET and ComedK UGET.

DTU is not private but a government college. As a SC student, you can only get admission to DTU having rank up to 2 lacs in JEE Mains.

BMS (VTU based) but if you would tell which branch then it would be easy to guide you.

Marks required to be eligible for these is 60% but some colleges require only 50%. It may be 5% low for SC/ST.
So, try to get a minimum score of 60%.
All the best.

SIT-Tumkur is better in terms of placement, faculty and location.