Hy ritika!!
As the result of class 12th has been declared by CBSE, now the asmission process will start in the colleges on the basis of 12th percentage. So may get the forms for bsc in ug courses either on the website of your desired college or you may get it offline also from the college campus. So start lookinh for the various colleges releasing their forms for admissions in undeegraduate courses in bsc discipline. Or you may directly contact the college for enquiring about the release of their admissions forms
Hope it helps
All the best