Hi Ambah - Does or will Aidyn be attending a Kindergarten before he goes to prep? I know that one of the teachers at my daughter's kindy was writing reports for those children that she did not feel were ready for grade one ( the parents agreed of course)
I think if you want to hold your child back - you have to get reports from your child's teacher, and a representative from Education Qld needs to do an assessment.
It is possible though, so I'm sure if Aidyn isn't ready at the time he's due to start prep, you should be able to do something about it.