(handy list)
Indian Railway - ministry of railways
http://www.indianrailways.gov.in/
Indian Railways reservation
http://www.indianrail.gov.in/
For pnr status
http://www.indianrail.gov.in/pnr_stat.html
IRCTC
http://www.irctc.co.in/
Mumbai Railway Vikas Corporation Ltd
http://www.mrvc.indianrail.gov.in/index1.htm
Metro Rail Kolkata
http://www.kolmetro.com/
Delhi Metro rail corporation Ltd
http://www.delhimetrorail.com/index.htm
North Eastern Railway
http://www.nerailway.gov.in/
Central Railway
http://www.centralrailwayonline.com/
Northern Railway
http://www.nr.indianrail.gov.in/
Southern Railway
http://www.southernrailway.gov.in/
Eastern Railway
http://www.easternrailway.gov.in/
Western Railway
http://www.wr.indianrail.gov.in/
Rail tourism
http://www.railtourismindia.com/
Darjeeling himalayan railway
http://www.dhr.in/
Train inquiry
http://www.trainenquiry.com/
.. if something is missed out do list it here..
