sure. u can get into unsw commerce and then major in acst with a uai lower than the cutoff by going well in relevant subjects (see unsw bonus points).
with macquarie u can't use bonus points to get into acst but you could always apply and hope u get a late round offer.
alternatively u could internally transfer if u manage to get into a lower degree @ the uni.
also ignore all this shit that people tell u like if u don't get 98.5+ u can't handle actuarial studies etc etc, it's all bs as uai means shit in uni. do whatever u can to get in, rort the system