For BSc, the combination of subjects usually differs from colleges to colleges. 

Some of the combinations that you can apply with physics, chemistry and biology in 12th standard are :- 

• Chemistry,  Botany,  Biochemistry 
• Chemistry, Botany, Zoology
• Chemistry, Botany ,Life Science 
• Chemistry ,Zoology, Life Science
• Chemistry, Life Science, Microbiology 
• Chemistry, Botany, Microbiology 

These are the usual subject combinations in various colleges for first year of BSc. 

Choose where your interest lies the most. The subjects in second year to be taken are 2 and then in third year one subject. 

If you still have any queries feel free to ask in the comment section down below.