Today (Aug 9) Australia reached a new low in T20Is by being dismissed for 62 by Bangladesh, who had won the series 4-1.
T20I statistics have now become quite meaningless with the advent of a large number of weak teams. This listing includes only matches between Test teams (and totals with 8 or more wickets down):
You can see that this 62 is Australia’s lowest T20I score. India is slightly better with 74 (though that was long ago).