There are a number of schemes available to unite children with their families visa immigration.
Child (Permanent) (Subclass 101)
For children from overseas who are the child or stepchild of an Australian citizen, Australian permanent resident or eligible New Zealand citizen.
Orphan Relative (Permanent) (Subclass 117)
For children from overseas whose parents are deceased, permanently incapacitated, or whose whereabouts are unknown and who have an eligible sponsor.
Adoption (Permanent) (Subclass 102)
In the case of the adoption of children from overseas by an Australian citizen, the holder of an Australian permanent visa, or an eligible New Zealand citizen.
Important: If the child was adopted before the parent became an Australian citizen, the holder of an Australian permanent visa, or an eligible New Zealand citizen they cannot apply for this visa. They must apply for a Child visa (subclass 101)
Dependent Child Visa (Subclass 445)
For children whose parent holds a temporary partner visa and is in the process of obtaining a permanent partner visa.
Humanitarian Program – Split Family Provisions
For the dependent children of people granted any permanent humanitarian visa (including Protection and Resolution of Status visas) in the last five years. Dependent children declared at the time of application may be eligible for entry to Australia through the offshore Humanitarian Program.
Visa Charges can be found here.