If you are or was a student of Royal University of Phnom Penh (RUPP), and you wish to apply for study abroad scholarship or admission, perhaps your school admission will require sealed and stamped transcript from your university. So if you happen to be in that situation or need some guidance on how to get your transcript done, I can give some tips for you as below. In my case, I apply for MS in Computer Science in Maharishi University of Management (MUM) which the school admission requires the sealed and stamped transcript from my university.
First, you need to get to office room #101 which responsible for any information related to computer science department in RUPP. Once you get there, you will see the admin (receptionist), and you can ask them that you want to make a transcript for studying abroad. They will redirect you room #105 to write the transcript form and pay the bill there. It costs 8000 Riels (~2$) per transcript, but make sure you input the correct information in request transcript form.
Once you pay the transcript payment, get the paper back to office #101, they will process this. It took about 7-10 days to get it done.