The TV presenter explained how their 11-year-old son Valentino "thrived" in a mainstream primary school, but secondary school was a "bigger animal".
The parents said they were recently told their son would "progress better" in a different school, but have struggled to find a suitable one for him to start at in September.
"We've been to see a lot of schools and it's been depressing," Sykes said on ITV's 'This Morning'.
"We've been down the right avenues, but some of the provisions for autistic children has been hellish with little understanding of what they actually need."
According to Sykes the issue with Valentino's current school is that his teacher said he was "just coping".
"The teacher said to us: 'Do you want him to just cope or do you want him to be enjoying it?'" Sykes explained.
"Tino is such a happy child and we're going through this drama and he doesn't know anything about it."
The couple said their son is considered "high functioning" so the issue lies in the fact he is "too high functioning" for a school with autistic children, but not high functioning enough for a mainstream school.
"It's been really hard. School life is supposed to reflect the bigger world when they go out of it," Caltagirone added.
"Schools should be integrating people and have awareness.
"It's not the teachers' fault, they are trying hard, but they haven't got the funding or resources.
"Tino just needs to be in a school suitable for him."
The couple said since they've gone public about their struggle to find a school, hundreds of other parents are coming froward in the same situation.
"We genuinely want to help other people, if we're not talking about it, it might not get talked about," Sykes added.
Sykes revealed she had to find a new school for her son in June 2016. At that time, Sarah Lambert, head of policy at the National Autistic Society, said Syke's experience was “all too familiar”.
“Exclusion should only ever be a last resort, but children on the autism spectrum in England are four times more likely to be excluded than children without special educational needs," Lambert told The Huffington Post UK at the time.
“We can’t know exactly what has happened in Melanie’s case. But, in our experience, exclusions are often due to the child not getting the support they need, either because of a lack of understanding of autism or because the placement is inappropriate.
“For instance, some autistic children are highly sensitive to things like light and sound and if this isn’t understood and addressed they can really struggle to learn and can become overwhelmed in school.
“Anyone who is in need of help and advice can get in touch with our Education Rights Service."
ITV's 'This Morning' is on weekdays from 10.30am.