What king of ball do they use in the game of rugby?

A Steeden football is used in Rugby League; a Gilbert football is used in Rugby Union and a Sherrin football is used in Australian Rules Football (AFL).

The Steeden football and Gilbert football are almost identical, such that goalkickers from the two rugby codes have had kick offs from different positions on the field, with League winning each time.

AFL is the oldest codified and registered game in the world. The Sherrin football is marginally different because AFL is a kicking game with players required to bounce the oval football when running like in Basketball, and they "fly" for a mark like in Union but they are usually on their own.