free ranging in the backyard he began to show signs of staggering and imbalance. This morning he seems a little worse and as the day has progressed he is now mainly just sitting and is unable to stand for very long....He is fed on laying hen crumble pellets and his water is infused with garlic chilli and apple cider vinegar, he free ranges in the back yard every day
Hi
@Nicho1511 
Welcome To BYC
Do you have a video of his actions or photos of him you would like to share?
How long has he been eating layer pellets? (for videos post to youtube or vimeo then provide us a link)
What other food/treats do you feed?
Can you take a fresh poop sample to a vet to rule out/confirm Coccidiosis or worms?
I'm sorry to hear that your cockerel is not doing well. You mention he free ranges the backyard - any possibility he ate anything toxic (fertilizer, rat poison, weed killer) or rotten (moldy vegetation or dead animal)?
It's possible that at his age he may have Marek's. If this is the case, the only thing you can do is offer supportive care, make him comfortable ensure he is eating/drinking. Some people do place them in a sling to help the legs move some.
There are other things that can mimic symptoms of Marek's, so you may want to look into those (see
@ChickenCanoe post above)
Provide B vitamins, get a fecal float, look him over for lice/mites, offer a diet with less calcium and higher protein like chick starter or flock raiser, check him over very carefully for any injury or wounds that may be hidden under the feathers, etc. If he declines further, talk to your vet or you may have to make a hard decision whether to continue to treat him or end his suffering.
Let us know how he's doing.