Hi,

Yes you can go for it without having physics and chemistry. The basic criteria in colleges like DU, Dehradun college, St. Stephen, Narseemonji is that you have maths in class 12th and you pass with a minimum of 50% in your board examination.
All you need is mathematics, one language subject (which counted as your main subject in 12th eg. English) and any two other main subjects. For BSC mathematics in University of Delhi best of four percentage is considered in the similar pattern as above.

Hope this helps.