Green’s Dictionary of Slang

confidence trickery; in weak sense, any form of ‘sharp practice’; also attrib.

1919		C. Drew The Doings of Dave 142 : ‘Melbourne [...] I’ve been down there doin’ a bit of rortin’.’ ‘What line are you on?’ ‘Clocks [...] the best line of clocks you ever slung your eyes on.’ [AND].
1941		Baker Popular Dict. Aus. Sl. 61: Rorting, shrewd practices, confidence trickery.
1997		Chesterman & Galligan Citizens without Rights 215: Anecdotes concerning rorting by ATSIC-funded groups have been used to support broader arguments about ATSIC’s structure being inappropriate for the management of public funds.
2000		Bug (Aus.) 24 Apr. 🌐 Hansie Cronje’s going to come out of whatever inquiry they set up to investigate these rorting claims looking sweeter than Greg Chappell at a fancy dress party.