Section 6(12)(b) in Tamil Nadu Motor Vehicles (Regulation and Control of School Buses) Special Rules, 2012
(b)The emergency exit shall be in the form of a frame fixed with a toughened glass with dimensions of 150cms x 120cms or in the form of a door with the same dimension hinged at the top, capable of being operated both from inside and outside. The words "Emergency Exit" shall be prominently inscribed in red colour on a white background both inside and outside of the emergency exit.