My research of the internet provides me: Tamil Brahmins as a whole (including both Iyers and Iyengars) make up less than 3% of Tamil Nadu’s total population.
Among them, Iyers, who follow the Smartha tradition and the Advaita Vedanta philosophy of Adi Shankara, are the primary Smartha group.
In certain regions like the Cauvery Delta districts—Thanjavur, Nagapattinam, Tiruvarur, and Tiruchirapalli—Iyers can form up to 10% of the local population.
In Nagercoil, they reportedly make up 13% of the city's population.
So while exact numbers are hard to pin down, Smartha Brahmins likely constitute less than 2% of the state’s population overall, with regional concentrations in historically significant temple towns.
Approximate Estimates:
In India, Brahmins make up less than 5% of the total population.
In the diaspora, estimates suggest that 10–15% or more of emigrated Indians may be Brahmins, depending on the country and migration wave.
All these statistics for what purpose?
What is it that you want to learn from this birth-based caste system? Does it have any significance?
One Baniya Modi is enough to become the Prime Minister. Caste has no meaning except for quota politics. What you achieve and become is your own karma. Caste is more div