Kilnathur BO is the primary post office registered under PIN code 606601 in Tiruvannamalai, Tamil Nadu. This code sits within the Southern Postal Region, with 7 offices operating under it.
| Post office | Type | Full name |
|---|---|---|
| Kilnathur BO | BO | Branch Post Office |
| Ayyankulam SO | SO | Sub Post Office |
| Tiruvannamalai RS SO | SO | Sub Post Office |
| Tiruvannamalai HO | HO | Head Post Office |
| Saron BO | BO | Branch Post Office |
| Kalnagar SO | SO | Sub Post Office |
| Tiruvannamalai Bazaar SO | SO | Sub Post Office |
