Hi Roshan. The NSW Vehicle Standards Information (VSI) 6 can be downloaded as a pdf by following this link. See p7, Item 13 for modifications permitted to tyres. VSI 9 is focused on wheels and tyres and that contains the technical specs for wheel/tyre combinations that project beyond the bodyline. Download this VSI as a pdf and check out p4 where the bodyline issue is referred to in the bullet points.
It took me a couple of days of checking and cross-checking to make sure I'd got my new combination right. Alternatively, as Dru suggests, you could ask the experts at ATV.