Tamil Nadu's 234 Assembly seats trace back to the Delimitation Commission that redistributed seats after the 1961 Census, chaired by Justice J.L. Kapur with C.P. Sinha and K.V.K. Sundaram.
- Under Article 170 and Section 8(b) of the Delimitation Commission Act, 1962, Assembly seats must be an integral multiple of a State's Lok Sabha seats.
- To limit losses for larger States, the Commission raised the total from 481 to 490; Madras still fell from 41 to 39 Lok Sabha seats.
- Keeping the multiple of five would have cut the Assembly from 206 to 195 (39 × 5).
- So, for Madras alone, the multiple was raised to six: 39 × 6 = 234, a figure unchanged six decades on.