Find post office by pincode 521138 in district Krishna in Andhra Pradesh, India using online India Pincode finder tool. There are around 4 post offices in district Krishna, Andhra Pradesh, India with similar pincode 521138. All the post offices with pincode 521138 in Krishna district of state Andhra Pradesh are listed above. Finding post office location by pincode is very easy, simply click on any one of the post offices listed above to get its details. For example, if you want to know post office details of Ayyanki, just click on the post office name.