What are the opportunities for IIT Madras biotechnology?

Frankly speaking, Biotechnology is yet to make it big at least in India. It's in its initial stage and still requires a lot of time to be at par with other branches of Engineering. India has little to offer in this field and thus job opportunities are limited or almost non-existent. 

Outside India, Biotechnology is in full bloom offering splendid courses in the most renowned foreign universities. One of its fields, Synthetic Biology is one of the most pursued fields abroad and offers excellent opportunities.

Here is the bright side, IIT Madras has ties with many foreign universities thus opening gates for its students to step out and gain exposure in the form of semester exchange programs which is not possible at IITR.

Let me warn you that Biotechnology as a field has limited or no placement scope owing to its research-oriented nature. So if it's a high salary you are after, it's not too late to look for another branch as this field is only for the passionate.