The Nattukottai Chettiars are divided among themselves on the basis of temples called “Nagara Kovils” (temples of Lord Shiva, since they are Saivaites). They are divided on the basis of nine temples that have many sub-divisions. Marriages can take place among the various divisions. One cannot enter into an alliance within the same division, but in some temples, if the sub-division is different, then the marriage can take place.
The temples are the places for the registering of marriages for the Nagarathars. On the day of the marriage or earlier, the bride's and the groom's side have to go to their respective temples to register their marriage. The bride would renounce her temple and would be enrolled with the groom. They become a proclaimed member of the community and are called a “Pulli”. The marriage becomes legally valid. On becoming a member, they start paying their annual subscription to the temple. From the temple, on registering, the couples are blessed with the offerings from the respective temples.
Inter-Kovil marriages are performed. Exemption: Pillaiyarpatti and Iraniyur will not have alliances between them as they have a brotherly relationship. No marriages are performed intra-branch, except in Illayathangudi and Mathur.