Thamarankottai is a village in Pattukkottai Taluk in the Thanjavur district, located in the delta of the Kaveri river.

Thamarankottai is the largest village in the Thanjavur district in terms of Area.

Melakkadu, Kezhakkadu and Rasiangadu are the hamlets of Thamarankottai North, while Sengapaduthankkadu, Manjavayal, Karisakkadu and Karungkulam are the hamlets of Thamarankottai South.

national census, Thamarankottai North has a population of 6,031, of which 2,872 are males and 3,159 are females.

Thamarankottai South has 4,499 people (2,156 males and 2,343 females) in 1,110 households across the four hamlets of Manjavayal, Sengapaduthankadu, Karungulam, Karisakadu, and Mankanangadu.