List of ports to use?

I intend to use port 6799 and likely a few ports below that number, like 98, 97 and 96.
I’m sure there must be someone else using these ports but I think it’s not a problem if the software is not a major software.

Is there a site where you can either register ports or look for used ports!?
How do you select ports?

There’s no official list, but Wikipedia has a pretty good approximation.

Thank you very much! In this link,

6792-6800 Unassigned

I’m sure they are used by someone, but at least not any major and consumer intense software!