I want to travel from Delhi to Jaipur by train, but I change my mind to travel by bus now. I need to cancel ticket and how much ticket money will be refunded to me?
This depends on multiple factors like which class the ticket belongs to, how many days prior to the date of journey are you performing the cancellation, whether the ticket is Tatkal (special quota for next day journeys) or Regular quota and whether the ticket status is confirmed, waiting or RAC (Reservation Against Cancellation), among others.
You can find an exhaustive list of rules for e-ticket cancellations. They are just a google away.
Note that you can always go to the irctc (the online ticketing portal) and try performing a cancellation. It should preview the exact amount before you finally submit.
Hope it helps.
[Edit]: There is no difference in cancellation policies with respect to the type of booking (online or counter ticket). I should have been more careful in providing the link. That was for employees to cancel on behalf of (hence the login) .
Try this website out for input on Indian Rail Travel. I understand that if you have gone through a travel agent, you must obtain any refund through them. http://erail.in/Rail/RailwayRefundCharges.aspx