For a particular station, there is fixed quantity of seats available. Here in this case, in Gwalior for this train 8 seats are available (as per rule one can book ticket before 4 months of journey). Hence, this availability is showing total no. of seats available in 3AC General quota from Gwalior. Rest of the seats are shared be all the stations in this journey.. Also to be noted that more no. of seats are available from originating station..