Think I answered another of your posts relatively recently re: similar issue.
I'd recommend that you check
here and
here for information on internal transfers (basically transferring from one degree at Monash to another) for Radiography. I'd also get in contact with Monash to confirm the provided and this information I've giving you, but it looks like you'l have to cover the Methods prereq through a first year uni equivalent (likely MTH1010) and still have competitive grades and possibly ATAR. The minimum is a 70+ WAM, but "competitive" grades are often 75+ WAM, which is typically above average.
Other options might be transferring through other health-related/ allied health degrees, doing an accepted undergrad degree and approaching a
postgrad version of the course, or find a bridging course, if that's possible.