Definitely not. Jab Tak Hai Jaan is purely a fictional tale. The plot, characters, and events are all made up to offer viewers an engaging and dramatic experience on the big screen.
Well, it has roots in reality. Umrao Jaan is believed to have been based on a real individual, but the story as we know it through different mediums has likely undergone creative alterations and interpretations.
Yes, it is. The movie takes inspiration from real-life events and characters, although it might have some fictional elements added for dramatic effect.