Section 216(1)(c) in The Bihar Motor Vehicles Rules, 1992
(c)When a motor vehicle is being towed by another motor vehicle, the clear distance between the rear or the front vehicle and the front of the rear vehicle shall at no time exceed 457 centimetres. Steps shall be taken to render the tow rope or chain easily distinguishable by other users of the road, there shall be clearly displayed on the rear of the vehicle being towed in black letters not less than 8 centimeters high and on a white ground the words 'ON TOW':