Mt Barrallier is just south of Mt Wallarra and almost completely surrounded by cliffs.
Heath almost totally blocks access to Mt Barrallier from the ridge running down off Sunshine Hill. A lot of effort is required to work your way through the heath.
There are a number of passes that provide access through the cliff lines and 2 of these allows you to avoid most of the heath. I have used the following passes at:
Images on Google Earth suggest that there might be passes near Shamash Point. These are not viable. Initially they look they will go but all have vertical rocks walls at the top that cannot easily be climbed.
Kanangra Tops (Dunphy)
Kanangra-Boyd National Park (NSW)