Hi

Bsc is a 3 year duration course. To be eligible for BSc you need a qualification of 10+2 in science stream. So you don't need to be a college passout to be eligible for BSc

Some examples of bsc includes Bsc physics,  Bsc maths , Bsc computer science,  Bsc in IT etc.

List of some top college for BSC  is provided below

Miranda House :- it is the best college you can get in the country for BSc ,it has been ranked 1 in NIRF ranking 2019.

Some, other top colleges are listed below:-

Hindu College
St Stephen's College
BHU
Madras Christian College
Loyola College
Hansraj College
St xaviers Kolkata
Christ University
Stella Maris College
Sri venkateswara College

I hope that you find this helpful dear

Thankyou