Fixed term agreement – you cannot make your tenant leave. They can stay until the end of their term and the new owner becomes the Landlord.
Periodic agreements – In the case of rental premises being sold and the new owner requesting the property be vacant, after the contracts of sale have been exchanged, you must give the tenant notice to vacate, at least:
NSW: 30 days written notice prioe to the end date of a fixed term agreement, 90 days notice for periodic agreements , using a Notice to Leave
QLD: 4 weeks written notice using a Notice to Leave (form 12)
VIC: 60 days written notice, using a Giving Notice to Vacate to Tenant/s of Rented Premises Form
WA: 30 days written notice, issue a Termination Notice (form 1C)
NT: 42 days written notice, using a Notice by Landlord to Terminate (form RT05).
TAS: 28 days written notice, using a Notice to Leave
SA: 60 days written notice, using a Notice of Termination by Landlord (form 3)