Section 159(1) in The Chhattisgarh Motor Vehicles Rules, 1994
(1)Every public service vehicle other than a motor cab or a maxi-cab shall have the following internal height or head-room measured along the centre of the vehicle from the top of the floor boards or battens to the under side of the roof support :(i)in the case of single decked vehicle and the lower deck of double decked vehicle not less than one hundred and seventy-five centimetres and not more than two hundred centimetres respectively;(ii)in the case of the upper deck of a double decked vehicle, not less than one hundred and seventy-two centimetres :Provided that the Regional Transport Authority may vary the above measurements in respect of any public service vehicle plying solely on any specified corporation or municipal or cantonment limits and environs thereof.
