TrainMan- 1 min
Trainman helps you to find alternate train bookings on the same route and train for Indian railways.
You can check it out at http://trainman.defcon007.com/.
Github - https://github.com/DefCon-007/trainman.
How it works
Let’s say your train starts at source station A and ends at destination startion F and follows the following path:
A -> B -> C -> D -> E -> F
Now you want to travel from B to D, but there is no ticket available. Indian trains have ticket quotas on the basis of stations. So, even if tickets from B to D are fully booked, you may get a reservation from any of the following routes in the same train :
A->D A->E A->F . . .
TrainMan lists availabitily on these kind of alternate routes to make your journey hassel free.