The Covid lockdowns played havoc with the production of the film. The post production was finally completed by the end of 2021.
For the Crown Heist sequence, a couple of the vintage train compartments were built on set. The rest of the train, and the terrain it travels on is computer generated.
Parts of the fort shown in the film was a set created at Film City in Mumbai where around 300 workers worked on it for 2 months. The rest of the fort, and the hilly environment around it was virtual, as were some other ‘locations’.