Hi, the admission process for part time language courses in Delhi University usually starts from mid June. To know about the application form you will have to contact the university you wish to get admission in to fill get the form and fill the same. I would advice that you make a lisi of colleges in which you would want to get admission in and whether the college offers certificate course in the language you are interested to learn and then constantly update yourself by visiting the websites of those universities for notification related to admission in part time language courses.

http://duupdates.in/language-courses-offered-in-du/ from this link you will find the colleges and the language courses they offer onm different levels(certificate/diploma/full time course etc)

Good Luck