Xbox gamertag isn't allowed but it isn't anything rude

It might mean something offensive in a different language or could be a word that is not allowed for religious or political reasons.

I checked everywhere but it doesn't seem offensive or anything like that so i'm not sure why it isn't allowing it but i want it

I am pretty sure it has nothing to do with copyright because I searched the word and it turns out to be a Japanese five needle pine. You could try changing the name from another device.

That can be for many reasons as explained in the xbox enforcement page. One of them includes copyright issues.

Most likely because it's too many characters. With the new gamertag system you can have 12.