Section 82(9)(o) in Delhi Motor Vehicles Rules, 1993
(o)that the licensee shall keep a complaint book which shall be given to the customers or the operators without any hesitation. It shall be open for inspection by any officer of Transport Department, so empowered by the Commissioner or by police officer in uniform not below the rank of Sub-Inspector. The complaint book shall be produced before the licensing authority at the time of renewal. If there is any serious complaint, the renewal shall be refused;