To clarify from moon rabbit's reply: this is for games that don't show language on no-intro database
Multilang games always specify every available language on no-intro, so if it doesn't specify a language it means it's only one language, and then you can generally know what that language is from the region code
Region code wont help if the game happens to be multilang, you need to check no-intro for that. So check no-intro first, then if the language isnt specified on no-intro, you can check region code