For NSW the RTA VSI06 says: "Maximum engine capacity ... Original tare mass (kg) x 3.0 cc". reportedly they accept 730kg for 1200 sedan/coupe resulting in 2190 cc max.

But "The engine capacity to be used for rotary engines is the displacement of all rotors x 2"

12A is 1146cc. So too big.

This is only for "for registration as a modified production vehicle". For ICV engineering it would be allowed, still could be street registered but will cost more.