In the final chapter, Bansal asks Jaskirat to be ready by 8 AM the next day for debriefing. However, Jaskirat goes AWOL instead and we see him boarding a train for Pathankot at Old Delhi railway station.
Now, the train he boards, I believe, is not conveniently made up for the story but is actually the Delhi-Pathankot SF express (22429) which departs Old Delhi at 08:15 AM. I know about this because I have travelled in the same train many times.
Assuming that the authorities only come to realise that he is missing after he doesn’t show up at the allotted time of 8 AM, the timing of Jaskirat leaving matches that of the departure of the real train.
I wanted to check when the train was inaugurated to see if it matched the movie timeline but I couldn’t find it. I may be wrong but if I am right, this is really peak detailing by Bravo Dhar! I also zoomed in on the image here to match the train number and was able to make out the “224” at least.