To extend your leave to remain in the UK to either attend your graduation ceremony or to continue your studies you need to contact the International Office. They operate a "Batch Scheme" and are happy to forward applications on to the Home Office.
They have lots of useful information on their web pages. If you can't find what you are looking for there, you can contact them at 18 Blenheim Terrace, Leeds. They are open between 10.00 and 15.30.
Gowns for graduation are supplied by Ede and Ravenscroft.
For further information please go to their website.
The schedules for the university graduation ceremonies can be found at: