Hello Surjeet, if You are from General, OBC,  category then you won't get admission in DU in any other colleges for B.Sc(Hons) in maths course. You might get admission in Bharati women's college if you are from SC category(the cutoff for last round was 73%), desbandhu college(the cutoff for last round was 70%) and some other colleges. Below is the link to last round cutoff list:

2018 DU 10th round cutoff: http://www.du.ac.in/du/uploads/Admissions/Cut-off/2018/10th%20Cut-Off%20-%20Science.pdf