You will need to be granted the permanent 888 visa before you can act as a sponsor for your parents in a parent visa application. Only Australian citizens or permanent residents can sponsor their parents.
At which point of my Australian 188 visa application can I apply for residency for my parents?
I am preparing for my 188 visa application. My parents are my only family members and I would like to know at which stage of the application can they get residency in Australia through my application.
188 visas are temporary residence visas. Only permanent resident visa holders are eligible to sponsor their parents for residency in Australia. After you have been granted the 888 visa, and can prove that you have lived in Australia for at least two years on a valid Australian visa whilst holding your 188 visa, you would be able to sponsor your parents immediately upon the grant of your permanent residence subclass 888 visa.
For Subclass 188 visas, one can add members of the family unit. However, parents are not considered as part of a family unit for visa purposes. Therefore parents must apply for a visa separately. Once your subclass 188 visa is granted, they can visit you in Australia on appropriate visitor visas. Once you meet the conditions of the subclass 188 Visa, you will be able to gain permanent residency by applying for a subclass 888 visa. As Australian permanent residents can sponsor their parents for a permanent Visa, you will be able to sponsor your parents to apply for an appropriate parent permanent visa once you have a subclass 888 visa.
You need to have been granted permanent residency before you can do it.