Hello, I am a co-owner of my clan and we are attempting to change our clan name to something to match our discord. The clan name we are looking for doesnt exist based on the rs3 clan home page. However the game isnt allowing us to change it to that. If a game/jagex mod can message me in game or via email that'd be awesome! thank you!
You are unlikely to get a response from a JMod here, and even if you did they are even less likely to change the name for you.
Clans with 5 or less members do not show on the clan home page, so there may well be a clan with the name you want already. The easiest way to find out is to try and guest in the clan chat.
If its taken and active, even with few members, then you have no chance in taking the name. Some people hold a clan name with only one person in the clan. There used to be a way to request the name be transferred from an inactive clan, but I don't think that that happens anymore.