The RSSP is a program for selected students to travel alone to Australia. While it is technically possible for selected RSSP students to sponsor family members later on for a humanitarian visa (Special Humanitarian Program), in reality this program is massively over subscribed and the wait times are very long.
Dependant family members (husband/wife/spouse and children) are prioritised for humanitarian visas. Extended family, including parents, are lower priority and would depend on availability in Australia’s humanitarian program.
There is no guarantee family members of RSSP students will be able to reunite permanently in Australia.