Here few two methods to verify the region, but it's based on wiiubrew database.
1) if you have the Title.tik, you can look inside to get the titleID.
Open the ticket in an hex editor and look at 0x1E0, the 4 first bytes are the Low TitleID part. 0005001B-LowID
Go to
http://wiiubrew.org/wiki/Title_database
search for your LowID and you'll get the region.
2) with your title key, you can also search on internet if you find the title key database, they will have a list of keys and their corresponding game and region.
3) If you have only the title key (not the full ticket) you can use Cdecrypt to extract only the /code/app.xml and look into it to get the LowID from title_ID node and look on wiiubrew too.
Cdecrypt will attempt to decrypt all the game, so you can to keep only partial files and do a "try and fail" method, but it's not the best idea. You can also look in the title.tmd to know which are the 2-3 first files to be decrypted (they usually are the /code/ folder) but you have to know where the content filename are stored. You can try to hint them with the .app size (very small, few Kb are usually the code folder)
But you usually have the title.tmd at this point, so you can look inside it instead of decrypting the game.
4) with title.tmd only
hex edit, and look at 0x18c and you'll get the titleID. check against wiiubrew too.