At the end of yesterday's Quanitco, Prime (Canberra) advertised that this week's episode would be the season final. IMBD says that there are still two episodes of Quantico still to run this season (Quantico and Inside). Both the Canberra Times guide and IceTV are showing Quantico at 21:30 Sun Dec 13 and then TBA at 22:30.
It looks possible that this may be a double episode final. IMDB says that Quantico "Inside" is due to screen (presumably in the US) on 10 Dec.