You are realising this very late. Please write an application to ggsipu.pr@rediffmail.com or pro@ipu.ac.in as soon as possible. Also, make sure to contact them through there helpine number +91-11-25302170. They will guide you. I would also recommend visiting the IPU head office if you do not get any reply. The address is Guru Gobind Singh Indraprastha University Sector - 16C, Dwarka, New Delhi - 110078 (India). Be quick and your problem might be resolved.