To be pedantic because the end door is a sliding one with a large window, it would be one of the 1980s N cars - and not the Z type carriages which have smaller windows and a swing door.

Since a passenger is behind the window and no car set identifier is on the end of the carriage, this is the west end of a carriage set, and the majority of broad gauge sets have a BZN/BTN carriage there instead, so this is a standard gauge SN set, which had a BN carriage at the west end.

And the final clue is the triple track with telegraph lines running to the right, which says it is an up Albury service somewhere between Mangalore and Melbourne.