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.
Choose the course you are interested in, as it will give you a comfort zone, once chosen the institute does not matter much.
If you are able to secure a seat in DTU, it should not be hard to get admission in a better college. So, you should try exploring other colleges preferably in the metros for the ease of networking and employment opportunities. Isolated colleges have their own flaws.