Car registration is issued by the relevant government body in each state - we don't have a choice of "provider", Tello.
In Victoria, registration is issued by VicRoads.
In Western Australia, it's issued by Licensing services (WA).
In the Northern Territory, Motor vehicle registry (NT).
In New South Wales, it's Roads and Traffic Authority, NSW.
In South Australia, it's the Motoring (SA) section of the SA govt.
In Queensland, it's Transport and Main Roads (Qld).
In Tasmania, it's Transport, DIER (Tas).
In the Australian Capital Territory, it's Rego.act.
My last rego cost $624.10 (paid annually).