Hi Ankush, first of all, on behalf of the EF Family, CONGRATULATIONS!!!
To be selected in the KGSP scholarship program is such a brilliant step to be closer to an institution that does not only spell SUCCESS but moreover, guarantees an experience of a life time. I know that you will cherish the opportunity given at this interview, now for some pointers and to address your mind - boggling - heart - pumping questions;
1. Will i compulsory to bring the copy of letter from supervisor in
Republic of Korea, Letter of Recommendation, Letter of
Self-Introduction, Statement of Purpose.? This letters and recommendation papers are definitely a must- bring to the interview, however, don't show them if they don't ask for it, remember, the less you talk and the less you initiate information, the better the chances of going into that circle of scholars, I have practiced this techniques on interviews and they absolutely work.
2. Will any written test be hold related to the field.?Well, for this question, as it is an interview, for my understanding and from experience, there will not be any written examinations, however, we will not be sure of what will transpire in the interview, so it's for you to find out.
Also, Ankush, I would like to remind you that the answers to your questions above is not base on facts, they are merely suggestions and anticipations as to what will transpire in the interview and it's all up to you to decide on what to do.
One thing is for sure, in an occasion where somebody will criticize you from head to toe and to the core of your brain, it's always and a must to BE YOURSELF and DO WHAT YOU THINK IS BEST, answer with a good heart and with an utmost intention for the good of the institution and for yourself.
The best of luck to you and do let us know what comes out of this interview, we would love to hear from you.