Since (almost all) Repatriation programs were Commonwealth Government activities, the records will be held in the NAA. You will need to use their RecordSearch tool find what is available.
If you would like to read a downloaded copy of the excellent 'Repat' A concise history of Repatriation in Australia then go to the website of the Department of Veteran's Affairs.
The historical photographs of repat programs from the first post-war years were from an NAA collection that can be located by an uncomplicated Advanced search for items. Note that the wildcard character (*) at the end of Album* simply indicates that want to see items from "all" the albums in the series.