India Post — regarding the parcel that is been held in the customs

I have bought few books and posters from gmarket, south korea. It is been held for an unspecified reason at the customs, when will i get the parcel?
Ems tracking number:eg[protected]kr
May i know when will i get it? It's last updated on 23rd april and not specifically told the reason for retention. I tried to contact several numbers and i didn't get response from any and mailed few and didn't receive any response..