There are some websites that are in Hangul. Hope the links help you. Wishing you good luck on your auditions

YG Entertainment

http://www.yg-audition.com/

(Information only in Korean)

Cube Entertainment

http://www.cubeent.co.kr/audition

(information is in Korean, not English)

DSP Entertainment

http://www.sendmall.co.kr/audition/main.asp

Starship Entertainment

http://www.starship-ent.com/audition.php

(Information is in Korean, not English)

Pledis Entertainment

http://www.pledis.co.kr/audition.php

(Information in Korean)

J.Tune Ent.

http://www.jtune.co.kr/pop_audition2.html

(Information in Korean)

TS Ent.

http://cafe.naver.com/tsent

(Information in Korean)

Star Empire Entertainment

http://www.starempire.co.kr/audition.htm

(Info in Korean)

NegaNetwork Ent.
Application form: http://www.neganetwork.com/audition/audition.php
(Info in Korean)

LOEN Entertainment
Website: http://www.iloen.com/
(They're not holding any auditions at the moment. It's possible that you could email your demo through their address: LoenEntertainment, Ltd. Production Business Team
1026-28, Banbae-3-dong, Seocho-gu. They recommend you in sending a demo cd (one Korean song and one pop song), your profile and photograph. I found this in their notices on their website.)