oh thats great you can apply in so many diffrent colleges in delhi for pesuing bsc maths hons

like:-

DU Delhi University..whic include many college like Hansraj college,deen dayal college ,daulat mal college and many college situated in north campus of DU.

further there are also south campus in which so many orther college available.

2. St.stephen college

and also many other private college are aslo available but you should mainly focus to DU north campus.