There is no license required in Queensland or Western Australia. Permits/Licenses are required in all other states.
Every state has different laws, so if you move interstate you cannot take your collection with you, unless you have the relevant permits/license for the state you are entering.
You can jump on your state police website and search Replica Pistols for what is required in your state.
Queensland - https://www.police.qld.gov.au/
Western Australia - https://www.police.wa.gov.au/
New South Wales - https://www.police.nsw.gov.au/
Victoria - https://www.police.vic.gov.au/
Australian Capital Territory - https://www.afp.gov.au/
Northern Territory - https://pfes.nt.gov.au/police
South Australia - https://www.police.sa.gov.au/
Tasmania - https://www.police.tas.gov.au/