Finding jobs in Korea largely depends on your major and your korean language skills. Let me know your area and will accordingly suggest you.
1) Firstly, Korean companies mostly need design engineers who could work on industry standard design tools and/or with programming skills.
2) If you are searching from Korea then with a help of Korean, you can register with www.jobkorea.kr or www.saramin.co.kr. You will surely get some response.
3) If you are searching from India, jobsites like www.naukri.com,www.mosterindia.com etc. are constantly posting some opening for Korea and you can apply through them
4) Also, from India itself, you can do KEYWORD search inwww.jobkorea.kr and can get email address of HR of the companies. This is a random try and so have to collect as many ids as possible and post your resume. Also, you can get some head hunter ids as well and if lucky enough, they will surely reach out to you with different openings.
5) FINALLY and MOST IMPORTANTLY, before trying for Korea, do a preliminary study on Skill sets required by Korean companies for your domain and make sure that your resume covers the skill set.