Hii Khushboo!
For DU SOL admissions, you need to fill the application forms after visiting the official website. The admissions for post graduate courses are provided in two ways, that is, based on merit list or entrance examination. You haven't mentioned the stream of subjects you want to study. So, you can visit the official Website and get more information.
https://sol.du.ac.in/home
Hope this helps.
Good luck!