Australia has recommendations. Basically anyone no matter the age can see anything from spy kids to confidence. then we have two restricted ratings: MA15+, must be 15 unless accompanied by adult, R18+, must be 18.
Generally, Australia is more lax with ratings than USA and UK. Things like Sin City got 18 in UK, but got MA15+ in Australia. We can't go higher than R18+, so it wont be a problem. The Australian R rating can handle alot. We got Ichi the killer uncut, although USA got it heavily cut and UK got it cut.