Section 17(1)(b) in The Delhi Police (Appointment & Recruitment) Rules, 1980
(b)The candidates selected for enlistment as constable (Drivers/Despatch Riders) from the open marked will undergo full recruitment training course which will also include training in driving/maintenance of vehicles. Candidates selected from amongst serving constables will only undergo 3 months training in driving maintenance of vehicles. However, ex-servicemen candidate will only be put through a short re-orientation course before posting them as a driver.