According to The Aviation Herald:
"The crew levelled off at FL120 to assess the situation, then decided to divert to Brisbane,QL (Australia). The aircraft climbed to FL240 for the flight to Brisbane and landed safely on Brisbane's runway 01 about 135 minutes after departure.
A passenger reported that there was an abnormal engine (V2527) sound during departure from Cairns, the crew subsequently diverted the aircraft to Brisbane."
Tigerair Airbus A320 VH-VNJ at Sydney in December 2014
At the time of posting, it is still on the ground at Brisbane (YBBN), however, Flightaware shows that the A320 is scheduled to operate an RPT (Regular Public Transport) flight to Melbourne Tullamarine (YMML) later today.