NC in a train ticket stands for "No Choice". It means that the passengers preferred berth choice was not available, and they were allotted a different berth. For example, if a passenger selected a lower berth as their preference during booking, but at the time of allotment, a lower berth was not available, then the ticket status would show NC. It can also indicate that a seat preference, such as a window seat, was not available, and another seat was allotted instead.