Homa.

Sudarśana Homa → auspicious purification/protection → wedding/upakarma-type ceremony

In many Sri Vaishnava families, a family undertaking a Sudarśana Homa before an important samskāra is understood not merely as "doing a homam," but as creating an auspicious ritual setting and seeking the Lord's protection before the major event.

The ratha procession adds another fascinating dimension. The temple chariot is itself a moving sacred structure: the deity who normally resides within the temple comes outward among the people. So we have:

the kuṇḍa — sacred space constructed according to measure

the ratha — sacred space set into motion

the temple — sacred space permanently established

No of bricks is specific for the conduction of the Homa. Their arrangements and other details are religiously followed to the T.