India Post
Not able to trace a registered post

I had posted one document from Deshbandhunagar Post Office (Pin 700 059) Kolkata on 11/12 with the number "AIR-RLB 3453"

I am not at all able to trace it now. Please note that it has a very important document in it and needs to be delivered at the earliest to Amsterdam, The Netherlands.

Could you please help resolve this issue at the earliest.