Section 50(2)(c) in The Central Motor Vehicles Rules, 1989
(c)the registration mark shall also be painted and exhibited on the partition provided between the driver and the passengers,facing the passengers seats or, where there is no such partition, on the front interior of the vehicle near the roof to the left side of the drivers seat facing the passengers seats in the case of a stage carriage or a contract carriage and in the case of a motor cab or a taxi cab it shall be sufficient if the registration mark is painted on the dash-board;