Hi, first of all both colleges are good and well known colleges and it's very much reasonable to choose IPU university, if you are getting admission in your desired course and if you feel that your chances in DU are less then you shouldn't risk loosing seat in an equally good college.

In order to decide which college you should take admission in, you can refer to DU's last year's cut off lists in order to have some idea about which list you can get admission, then comoare the colleges in terms of academic/syllabus for your course, read reviews about faculty members, college life, ectra curricular activities available(if you are interested in taking part), placements for your course(if any).

You can confirm your admission in IPU and if later on you get admission in a good DU college, you can always withdram your admission, but before than confirm about the last date to withdraw admission, refund of fees and the withdrawal process from the University.

Good Luck