If your registration form is not complete, you can access it through the tab Registrations
Depending on how far you are on your registration process, the tab Registrations may not be accessible to you any more. If you still need to upload documents, open the tab My students documents
Then click on Missing documents for my registration > If this is not your first year at RSB you have to click on Edit next to this years program
You will find many slots to upload your documents.