Although it is displayed on Steam, VR Chat itself does not support Korean.
However, since there are many maps made by Koreans in Korean, you can play on Korean maps.
But first, you need to set some basic settings in the options, but since that is in English, you will need some explanation in Korean.
There is an English tutorial when you start the game, but quickly get out of it and go to your personal homepage.
Press the [ESC] key on the keyboard. Then a menu window appears.
There will be Worlds in the quick links on the launchpad. Just press that first.
Please click on the red square I marked with Paint. This is a button to search the world.
Then a search box will pop up, enter korean here and search.
Then there is a VR Chat Korean Tutorial, click on it.
Click Join to enter, or click Drop Portal to install a portal on the map and guide others to the map.
And if there are already people on the map, you can create a new map without people by clicking New Instance.
And it's a new world that was recently created, so someone created a new tutorial? I recommend visiting here after completing the Hangul tutorial above. The PC version also has more useful information.
Once you try these two tutorials, you will be able to play in Korean without any problems even in VR chat, which is mostly English. No matter who the creator is, he chose many Korean maps for the tutorial map theme and installed a fixed portal inside. Of course, the map supports Korean hehe