how long it takes to get hong kong tourist vsa from australia with nepalese passport?

Hi there! As your relatives are HK ID holders, actually you can ask your relatives to submit the application to the HK Immigration Office for you. Or you can submit it to the office or the Chinese embassy in Australia by yourself. If the application is handled by the Chinese embassy, it's possible that you only need to wait for four working days. If the application is sent to HK side, it takes about four to six weeks for the processing.

If you plan to stay at your relative's house, the hotel reservation is not required. And you may need to provide an invitation letter from your relative.