The Strata Managers often place signage on the building, typically near the entry door or the car park entry. Alternatively, if you can gain access, have a look at the Owners Corpration’s Notice Board.
PS – I just realised that it may be the Managing (Rental) Agent of an adjoining Lot that you wish to contact, in which case YOUR Strata Manager may have received the prescribed Tenancy Notification under Sect 119 of the NSW Strata Schemes Management Act, so try that approach.