I am an intl student graduated from one of these Chinese Universities (PKU / Tsinghua / Renmin) and I am currently doing graduate studies in Korea. (Nationality: Korean)

I have internship experiences not directly related to law and am wishing to apply for T14.

I don't hold a legal certificate so I was wondering what's the chance of getting in to T14 ?

Even if your major is not law and you are not qualified as a lawyer, you can still get into T14 schools with good application. But sadly possibility of admission to T6 schools is very low in that case. Consider applying not only to T14 but also for top 30 law schools.