There are some Indian Railway websites, allows to check seat availability, PNR Status, trains between stations, train running status and all those related activities.
The useful website of Indian Railways
1. PNR status, Train between stations, Seat Availability and Fare enquiry
2. Centralized database of Indian Railways: PNR status & predictions , Station & Train info, Train between stations, Seat Availability and Fare enquiry
3. Online railway ticket booking
4. Indian Railways Trains, Rail, IRCTC Reservation, IRCTC Availability, PNR Status, Running Status, Map, Arrival Departure, Route, Fare Check
5. Train running status, Live station, Train schedule, Train reschedule, Cancelled & Diverted Trains
Please feel free to write your comments, suggestions or corrections.