I am currently in my 3rd year of Law/Commerce at Monash, having graduated with an ATAR of 84 and transferring into the course last year, from my perspective you would make it in with a 97.9. Ultimately it depends on how many people apply to the course, as the first round usually fills up with those who have the higher atars and go from there.
Honestly though you should be fine, if not, just do the same degree at another university and transfer into monash from there, they have applications open between 1st-2nd years i'm pretty sure, mid-year and end of year.
Good luck with it