I am getting computer science engineering at GNDU Amritsar and biotechnology at NIT Jalandhar. Which one should I prefer?

The choice mainly depends on the individual as both disciplines are entirely different. Firstly decide if you want a career in the corporate industry or not. Biotechnology is a very good subject with numerous opportunities, but it lags a bit behind in the Indian market. 

On the other hand, there is a huge demand for CSE graduates both in India and abroad. Due to the immense popularity of and sudden rise of IT firms, there are many opportunities. You will never have to struggle to get a job in a reputed company.

Placements are better for CSE graduates than Biotechnology graduates. Choose the one that suits your interest.