Can seat availability increase after being full?

Yes, seat availability can increase after a train shows fully booked because of cancellations, quota releases, or emergency quotas activated by the railway. Many passengers book multiple tickets as backup and cancel the ones they do not need, which frees up berths. The railway also holds a certain number of seats under different quotas such as general, ladies, senior citizen, and foreign tourist quotas, and when these quotas are not fully used, the unsold seats are released into the general pool. VIP and emergency quotas may also be released closer to the departure date if they remain unutilized.