If you know your password and log in you can just go down the server list. If you knew your original server you can Google everquest server merge list any comes back with a couple top replies . If you're talking about recovering an account there is a frequently asked question topic on this in the help forums.
If you still own the email the account was registered to, account retrieval should be trivial. For which server merged into which, this: https://help.daybreakgames.com/hc/en-us/articles/231264868-Server-Merge-History
