Hello,

With 280, marks you have chances of getting dual degree program in M.Sc. at BITS Pilani, Hyderabad Campus. You may get M.Sc. Biological Sciences, M.Sc. Chemistry at BITS Pilani, Hyderabad Campus. You may also get M.Sc. Biological sciences at BITS Pilani, Goa Campus. Well, since you know cutoffs depend upon several factors like number if students appearing for the exam, number of seats available etc  prediction of exact branch would be difficult as of now. But you have high chances of getting admission in BITS. 

Hope this helps. Regards