Summary Proceedings Act 1957, s 88AE
Getting a fine “remitted” means that a judge makes an order that you don’t have to pay it or, if you’ve already paid some of it, that you don’t need to pay any more. In other words, the fine is wiped.
A judge might do this because:
you’re going to do some community work instead of paying the fine, or
you’re going to do a few days or weeks in prison instead of paying the fine, or
the judge decides that in your case it’s fair and appropriate that your fine is wiped.