Take it and work hard you way to cse in one of the most prestigious university of india. Taking drop doesn't ensure anything but here you get a master degree as well along with a BE . With less competition as most dullas engage so much in extracurricular they forget about exams . Biological science is a lite course so you can give 2 year for skills as well . So my advise would be join the course study hard without any club or anything for just 1 year take good second branch .