Australians were mostly issued with US M3 Lights, M3 Mediums, and British Matildas for action. A few cavalry units used Vickers Mark II Mediums and Mark VI Light Tanks on top of their fleets of Universal Carriers. In Tobruk, there were no Australian "tanker" units per se, but the 6th Cavalry Regiment used a few captured Italian M11 tanks in the city's defense.

Any proper armored units either ended up in home defense or serving in the PTO. The Australian 1st Armored Division used mostly M3 "Stuart" Light Tanks and M3 "Grant" (British variant of the US M3 "Lee") Medium Tanks. Only a few regiments were broken off to see action, and they mostly used the Stuarts and Matildas in their service. There were a 2nd a 3rd Armored Division. Neither saw action until the 3rd was dissolved and the 2nd was downsized into the 4th Armored Brigade. This unit saw action in New Guinea, Borneo, and Malaysia. Outside of Buna where the M3 Stuarts mostly got used, Matildas got used the most by the Australians in the PTO in combat. They also had their own home-grown flamethrower variant named the Frog, which was supposedly very successful in the later parts of the war. I've never seen anything to suggest the Grants got used in action. They also received a handful of Shermans and Churchills for research trials.

There was one Australian-made tank of that time period, the ACI Sentinel. Australia couldn't really rationalize a home-grown tank program once it could get Stuarts, Grants, and Matildas in large numbers. The Sentinel pretty much existed for the sake of armor research, or eventually serving as movie props.