Before how many days can we book the ticket.
Advance tickets can be booked 120 days advance from the departure date of originating station
You can reserve your ticket 120 days in advance, excluding the date of journey at the train originating station. At intermediate stations where the train arrives the following day, reservation can
be done 121 days in advance. In the case of some intercity day express trains, the advance
reservation period is less.
However foreign tourists can book tickets in Foreign Tourist quota upto 360 days in advance.