You can go as long as you pass the exam.
If you know Korean, you can go directly to the undergraduate course, otherwise you have to take a language class for one year first.
The way is to find an intermediary and go through the formalities.
There is also the latest policy. Some schools will start to look at the results of the college entrance examination this year.
This policy may be promoted one after another, and it is only a part of schools at present.
So, let's go before it's too late.
I will go in September this year.