Hi

So to get entry ticked into IISc after 12 

Candidate needs and answer and crack any one of the following exam

1. KVPY

2. IIT JEE

3. NEET

The candidate can get admission into Baclelor of science ( research ) in following subjects

1. Biology

2. chemistry

3. Earth and Environmental studies

4. Materials

5. Mathematics

6. Physics

So this the only entry point after 12 science