I am prettu sure they would just go into the grade where they fit age appropriatly.. My son who was 5 in August starts school next year. when my eldest started schol he went to Preschool at aged 4.5 and is now in yr 6. If they had prep in when he was to start he would only be in yr 5 now...

Maybe ring a school close to where you are looking to live to clear up any confusion