Recently i had to catch "Shatabdi" trian from Kanpur with in just 2 hrs of making the plan for the trip. I was not having any reservation. Current reservation worked for me (Kanpur to N.Delhi).
One can check the current reservation for a train on a specific station at this link;
Here you need to enter the station name you want to get current reservation from. Also there is no extra change for "Shatabdi" at least. One more thing current reservation can only be done from that station only from where the journey needs to be started. And the counter will be there on the station itself. In Kanpur the current reservation counter is on the entrance of Platform 1 only. (It might change in future, so better ask someone there on the platform itself.)
