Domain names are registered on a first-come, first-served basis. As long as the current registrant meets the eligibility requirements, they are entitled to retain the domain name.
If the domain you want is already registered, you may try contacting the current owner to see if they’re willing to transfer it. However, please note that they are under no obligation to do so.
Important for .au domains:
The sale or transfer of .au domain names for profit is prohibited. Any individual found selling a .au domain name risks having their licence revoked by auDA (the official .au domain administrator).
All other domain types (such as .com, .net, etc.) may be freely sold or transferred between parties.
