Hi there, this is Dr Linda, a UK based vet.
I'm sorry to hear this and understand your concern for the cat.
If he has not been neutered, this will go a long way towards explaining the repeated fights and puts him at thigh risk for future fights, sexually transmitted diseases and car accidents.
With regards ***** ***** it sounds like he needs antibiotics and anti inflammatories as well as a deep cleaning of the wound. Please feel welcome to send any photos for assessment.
As the lesion is near the eye, we need to stain it for any ulcers in case of damage. If there is an ulcer, the prompt application of topical antibiotics is very important.
In situations like this, you can call a local vet and ask if you can bring him in. If they are happy to see him and you can bring him in, this is the quickest way to get him help.
He should be neutered and medication will be started.
If you can afford the bill and are willing to pay, excellent.
Understandably, if not, you can contact the RSPCA. They can often offer a PO number to fund some or all of the treatment.
An alternative is to call the RSPCA and ask for a warden to come and collect him and bring him to the local hospital for treatment. They will neuter him too.
All vets will also scan for a microchip; just in case!