The admission fees of Delhi University is very less compared to other universities, also it depends from college to college, suppose you opt for arts course the fees for the course would be around 9–12k for a year.
After passing the cut-off go to the particular college in which you cleared the cut-off look for help desk and the first thing you would do there is to get an admission form and brochure.
After filling the form, you will have your documents verified and once all the process is done you can submit the fees and then your admission is done. You will be notified about orientation at the same day or you can check about orientation or time table on college’s website.
Hope it helps.
All the best!