@Kamesh Krishnamoorthy: Re# 141869-0
It is applicabe for all confirmed tickets. If your Ticket is in WL but confirmed at the time of charting, u r also eligible for upgradation. Please note that, there needs to be vacancy in the higher class
It is randomly decided by the system.
U may be upgarded upto two classes in a train.
I...
more... believe, it is random. No logic for Upgradation.
Even if there is a logic, it wont be available to general public. In that case, if we were to know the logic, we would go for that method. It is beeter to be surprised with Upgradation.