Dhvaja Stambha, or Flag Staff, is an important feature of most South Indian Temples. In North Indian Temples, flags are hoisted from a section of the main temple and rarely do we see a separate flag pole or Dhwaja Stambha. The flag staff is located in front of the Sanctum. There is no major symbolism attributed to the flag staff in a temple (flag of a temple do have symbolism attached to it). A Dhvaja Stamba usually represents the prosperity and pride of a temple. But some texts do suggest that the bottom of a flag post symbolizes Shiva, middle portion Brahma and the top portion Vishnu.
A permanent Dvaja Stambha is believed to be a later addition to the
. Initially, it was temporary and was primarily used to indicate the beginning of a festival or other auspicious days and occasions. Hindu Temple
Today, Dvaja Stambhas are a permanent feature in many south Indian temples and are gold or silver plated or covered with copper or brass. The top portion of the flag staff in some temples in Andhra Pradesh, Karnataka and Tamil Nadu has three horizontal perches or three branches pointing towards the Sanctum. It symbolizes righteousness, reputation and propriety or the Trimurtis – Vishnu, Brahma and Shiva. Usually, a Bali Pitha is located near to the Dvaja Stamba and the Sanctum.
But the three branches are not widely found in the temples in Kerala. Instead, in Kerala Temples it is a single straight pole.
There is a widespread belief that the Dvaja Stambha gives an idea to a devotee from a long distance about the idol installed in the temple and about the Vahana or Vehicle used by the deity. It also announces about a festival in a temple. Flags are usually hoisted when there is an auspicious ceremony or festival in the temple.
(Reference: Indian Temple Traditions – Kalpatharu Research Academy)