The requests for reservation at the reservation counters are accepted up to 4 hours before the scheduled departure of the train, after which, the reservation will be done at the current counters at the stations up to one hour before the scheduled departure of the train and thereafter by the Ticket Collector/Conductor on the platform, if vacant berths/seats are available.
.
But in practical current booking is done at counter till 30~15 Min before departure of train.