Some of the courses that you can take in Indian Institute of Technology as a Biology student apart from a B.Tech in Bioengineering are as follows:

Bachelor of Science + Master of Science (BS + MS) in Physics, Chemistry, Biology, Life Sciences

M.Sc. in Physics
M.Sc. in Chemistry
M.Sc. in Biology

PhD in Physics
PhD in Chemistry
PhD in Biology

Hope I have answered your question. All the best!