If you intend to apply to stay in Hong Kong under the IANG but have not yet received the result of graduation, you may apply for an interim extension of stay at the Immigration Department. You need to bring along the travel document and HKID card upon application. The Immigration Department will normally grant a 3-month interim extension to eligible students.
The interim visa, however, does not entitle you to study or work in Hong Kong. You should apply for such an extension only after you have completed all coursework and examinations. And once it is confirmed that you need to continue to study, you should apply for student visa extension immediately (Please read Q6 above for steps to extend your student visa). Before your application for student visa extension, or for staying under the IANG, is approved by the Immigration Department, you should not attend classes at the University or start working in a job.
To apply for the stay under the IANG or the interim extension, you do not need a supporting letter from the Academic Registry.