Travel while on subclass 866 visa.
If you hold a subclass 866 Protection visa, you cannot travel to the country you are seeking asylum from without permission from the Australian Immigration department.
This applies even if your family lives there.
However, there have been rare situations where substantial compassionate or compelling reasons for that travel, have permitted this travel. But, that permission must be applied for and you must get approval in writing before travelling.
Why is this condition?
As an asylum seeker, you are declaring that you cannot go home without facing a real risk of significant harm or persecution.
Other Notes regarding subclass 866 visa.
If you can legally enter and safely live in another country (apart from your home country), you will not get a Protection visa.
immi.homeaffairs.gov.au