what shoule be a right approach to the interview board while I have quitted the job that i have not disclosed?

Answer 1

Probably this particular question may NOT come out in interview.

If coincidentally, you are called upon to comment, it is better not to lie. Non revelations of fact maybe okay but wrong presentation of facts may create problems in long run.
If you are compelled to explain :
(1)If you were working somewhere which you did not mention in application, explain, that I did not mention because I was likely to leave that job.
(2) If you had already quited job before submission of application but mentioned that you were still working and omitted to mention
the quitting - explain my leaving job was not full and final.

TRY TO AVOID this type of situation in future.

BEST OF LUCK

Answer 2

I don't know dude.