Hii Vinayak,

Let me give you a short description about both of them:

Radio technology:In this you will learn about communication signals,EM waves,Communication satellites etc.

Biotechnology:It is also called life science or genetic engineering.Here you learn about  exploiting cell and tissue culture technolgies to produce new things.

So,you see both are completely different!! If you are interested in pharmacy then go for Biotechnology but if you are interested in knowing about waves,signals etc then definitely go for Radio technology.

But there is a problem with radio technology! This is very rare course that's why very few colleges provide this course.

If you are wondering about career opportunities then i must tell you both have a good career options.

Good Luck!