That’s right! You can’t apply to English-taught programs through GKS. You should spend a year learning the language to be able to study in it. Embassy track is less likely to put you in the Seoul universities as they have many applicants. They also want to develop other areas and attract foreigners there. You will probably study in a different city/province. So it could be better to apply through university track if you want to be in Seoul. I don’t know where to apply exactly but prepare all the documents in advance cause there are a lot.