Indian Railways is divided for administrative convenience into several regional railways. Until recently there were 9 zones, and this structure had not changed much for four decades. Recently, 7 new zones have been created, giving a total of 16.
The nine older railway zones are:
Northern Railway (NR)
North Eastern Railway (NER)
Northeast Frontier Railway (NFR, sometimes NEFR)
Western Railway (WR)
Southern Railway (SR)
South Central Railway (SCR)
South Eastern Railway (SER)
Eastern Railway (ER)
Central Railway (CR)
The 7 new zones are:
South Western Railway (SWR)
North Western Railway (NWR)
West Central Railway (WCR)
North Central Railway (NCR)
South East Central Railway (SECR)
East Coast Railway (ECoR)
East Central Railway (ECR)