You’ll have a relatively good chance with Monash, a slightly lower chance for Melbourne. If you also have Monash Guarantee/ Access Melbourne or any bonus points from SEAS or subject bonuses (which UoM generally don’t have subject bonuses), your chances of getting in will increase.
Hope that helps and congrats on your marks! 😀
Edit: For some stats - Monash currently has 91 lowest selection rank for Biomed, but have also been recently receiving students with late 80s ATARs (raw) with a few bonus points from SEAS and subject bonuses.
Melbourne Biomed currently has a 95 selection rank (with bonus points included already) and have had variable raw ATARs these past few years.