<P> Each of the divisions is headed by a Divisional Railway Manager (DRM), who reports to the General Manager (GM) of the zone . A DRM can be appointed from any of the eight organized services of Indian Railways, viz . Indian Railway Traffic Service (IRTS), Indian Railway Accounts Service (IRAS), Indian Railway Personnel Service (IRPS), Indian Railway Service of Engineers (IRSE), Indian Railway Service of Mechanical Engineers (IRSME), Indian Railway Service of Electrical Engineers (IRSEE), Indian Railway Service of Signal Engineers (IRSSE) and Indian Railway Stores Service (IRSS) for the tenure of three years, but it can be exceeded on the recommendation of Railway Board . The DRM is assisted by one or two Additional Divisional Railway Managers (ADRM) in the working of the division . </P> <P> Divisional officers heading all departments viz . engineering, mechanical, electrical, signal and telecommunication, accounts, personnel, operating, commercial, safety, medical, security branches report to the Divisional Railway Manager . </P> <P> The 16 zones and the 68 divisions are listed below, Kolkata Metro is the 17th zone: </P> <Table> List of IR Zones <Tr> <Th> Railway Zoe </Th> <Th> Code </Th> <Th> Zone Headquarters </Th> <Th_colspan="4"> Operational Statistics (in FY 2011 - 12) </Th> <Th> Railway Divisions </Th> </Tr> <Tr> <Th> Route length (km) </Th> <Th> Number of Stations </Th> <Th> Revenue </Th> <Th> Passenger Carried (million) </Th> </Tr> <Tr> <Td> 01 . Northern Railway </Td> <Td> NR </Td> <Td> Delhi </Td> <Td> 6,968 </Td> <Td> 1142 </Td> <Td> ₹ 89,246 million (US $1.2 billion) </Td> <Td> 685 </Td> <Td> Delhi, Ambala, Firozpur, Lucknow NR, Moradabad </Td> </Tr> <Tr> <Td> 02 . North Eastern Railway </Td> <Td> NER </Td> <Td> Gorakhpur </Td> <Td> 3,667 </Td> <Td> 537 </Td> <Td> ₹ 17,667 million (US $250 million) </Td> <Td> 250 </Td> <Td> Izzatnagar, Lucknow NER, Varanasi </Td> </Tr> <Tr> <Td> 03 . Northeast Frontier Railway </Td> <Td> NFR </Td> <Td> Guwahati </Td> <Td> 3,907 </Td> <Td> 690 </Td> <Td> ₹ 21,079 million (US $290 million) </Td> <Td> 88 </Td> <Td> Alipurduar, Katihar, Rangiya, Lumding, Tinsukia </Td> </Tr> <Tr> <Td> 04 . Eastern Railway </Td> <Td> ER </Td> <Td> Kolkata </Td> <Td> 2,414 </Td> <Td> 576 </Td> <Td> ₹ 37,254 million (US $520 million) </Td> <Td> 1,173 </Td> <Td> Howrah, Sealdah, Asansol, Malda </Td> </Tr> <Tr> <Td> 05 . South Eastern Railway </Td> <Td> SER </Td> <Td> Kolkata </Td> <Td> 2,631 </Td> <Td> 353 </Td> <Td> ₹ 73,721 million (US $1.0 billion) </Td> <Td> 263 </Td> <Td> Adra, Chakradharpur, Kharagpur, Ranchi </Td> </Tr> <Tr> <Td> 06 . South Central Railway </Td> <Td> SCR </Td> <Td> Secunderabad </Td> <Td> 6,137 </Td> <Td> 883 </Td> <Td> ₹ 89,114 million (US $1.2 billion) </Td> <Td> 378 </Td> <Td> Secunderabad, Hyderabad, Vijayawada, Guntakal, Guntur, Nanded </Td> </Tr> <Tr> <Td> 07 . Southern Railway </Td> <Td> SR </Td> <Td> Chennai </Td> <Td> 6,844 </Td> <Td> 890 </Td> <Td> ₹ 81,820 million (US $1.1 billion) </Td> <Td> 406 </Td> <Td> Chennai, Tiruchirappalli, Madurai, Palakkad, Salem, Thiruvananthapuram </Td> </Tr> <Tr> <Td> 08 . Central Railway </Td> <Td> CR </Td> <Td> Mumbai </Td> <Td> 3,905 </Td> <Td> 612 </Td> <Td> ₹ 75,447 million (US $1.1 billion) </Td> <Td> 1,675 </Td> <Td> Mumbai, Bhusawal, Pune, Solapur, Nagpur </Td> </Tr> <Tr> <Td> 09 . Western Railway </Td> <Td> WR </Td> <Td> Mumbai </Td> <Td> 6,182 </Td> <Td> 1046 </Td> <Td> ₹ 82,167 million (US $1.1 billion) </Td> <Td> 1,654 </Td> <Td> Mumbai WR, Ratlam, Ahmedabad, Rajkot, Bhavnagar, Vadodara </Td> </Tr> <Tr> <Td> 10 . South Western Railway </Td> <Td> SWR </Td> <Td> Hubballi </Td> <Td> 3,177 </Td> <Td> 456 </Td> <Td> ₹ 26,384 million (US $370 million) </Td> <Td> 181 </Td> <Td> Hubballi, Bengaluru, Mysuru, </Td> </Tr> <Tr> <Td> 11 . North Western Railway </Td> <Td> NWR </Td> <Td> Jaipur </Td> <Td> 5,459 </Td> <Td> 663 </Td> <Td> ₹ 36,240 million (US $500 million) </Td> <Td> 157 </Td> <Td> Jaipur, Ajmer, Bikaner, Jodhpur </Td> </Tr> <Tr> <Td> 12 . West Central Railway </Td> <Td> WCR </Td> <Td> Jabalpur </Td> <Td> 2,965 </Td> <Td> 372 </Td> <Td> ₹ 65,135 million (US $910 million) </Td> <Td> 138 </Td> <Td> Jabalpur, Bhopal, Kota </Td> </Tr> <Tr> <Td> 13 . North Central Railway </Td> <Td> NCR </Td> <Td> Allahabad </Td> <Td> 3,151 </Td> <Td> 435 </Td> <Td> ₹ 87,796 million (US $1.2 billion) </Td> <Td> 182 </Td> <Td> Allahabad, Agra, Jhansi </Td> </Tr> <Tr> <Td> 14 . South East Central Railway </Td> <Td> SECR </Td> <Td> Bilaspur </Td> <Td> 2,447 </Td> <Td> 358 </Td> <Td> ₹ 63,402 million (US $880 million) </Td> <Td> 126 </Td> <Td> Bilaspur, Raipur, Nagpur SEC </Td> </Tr> <Tr> <Td> 15 . East Coast Railway </Td> <Td> ECoR </Td> <Td> Bhubaneswar </Td> <Td> 2,572 </Td> <Td> 342 </Td> <Td> ₹ 87,884 million (US $1.2 billion) </Td> <Td> 86 </Td> <Td> Khurda Road, Sambalpur, Waltair </Td> </Tr> <Tr> <Td> 16 . East Central Railway </Td> <Td> ECR </Td> <Td> Hajipur </Td> <Td> 3,628 </Td> <Td> 800 </Td> <Td> ₹ 59,386 million (US $830 million) </Td> <Td> 222 </Td> <Td> Danapur, Dhanbad, Mughalsarai, Samastipur, Sonpur </Td> </Tr> </Table>

Which is the largest zone in indian railway