Section 142(2)(c) in The Haryana Motor Vehicles Rules, 1993
(c)the horizontal distance from the nearest point of the riser of the top step to the vertical line passing through the nearest point of the seat opposite to the top tread of the staircase excluding any grab rail which does not project more than 75 millimetres from the back of the seat, shall not be less than 660 millimetres; and