There are many walks around Australia happening, mostly in major cities or regional hubs. If you don't live in a region where this is occuring, perhaps you could organise your community to do something on Palm Sunday (14th April) to support justice for refugees and people seeking asylum. This could be a walk, a prayer during the Sunday service, or a circle of silence after mass.
ARAN have a list of events here: https://australianrefugeeactionnetwork.wordpress.com/news/ - scroll down to the 'Palm Sunday Walks' section.