You must be either
1. an Australian permanent resident
2. a former Australian permanent resident whose last permanent visa was not cancelled
3. a former Australian citizen who lost or renounced Australian citizenship. Australian citizens are not eligible to apply for an RRV.
If you are already in Australia as a permanent visa holder, you do not need to apply for this visa unless you wish to leave and re-enter Australia as a permanent resident.
With this visa, you can
1. travel in and out of Australia as many times as you want until the travel validity expires
2. have a travel facility up to 5 years depending on your circumstances. See About this visa.