It's my opinion that children with Autism Spectrum Disorders do well in either Autism specific schools (we need more of these) or in mainstream schools with support from Special Education Unit teachers. TA's (Teacher Aides) are also available here.
It is adviseable once you narrow down the selection of schools that you wish your child to attend, to find out if the school has an Autism Coding (has teachers that are experienced with children on the spectrum). Talk to the Principal of the school / email them.
Generally, a child with ASD cannot attend special school unless they meet the full eligibility criteria, one of which is that they must have an II (Intellectual Impairment) in addition to the neurological disorder of Autism Spectrum Disorder.
Our eldest son attends our local special school as he has an II and is only just starting to communicate verbally but is way behind his mainstream counterparts.
Mum to DS12yrs, II ASD and DS9yrs, HF.ASD,ADD,GDD.