“Ranbir coined the name on the sets of the movie when both were required to shoot for an action sequence,” said a unit source.
For the scene, Katrina and Ranbir were required to climb a ladder placed at a height of 200 feet. Ranbir had to save Katrina from goons and then escape on a jet ski. While everyone was doubtful about Katrina doing the stunt, she shocked everyone with her confidence.
“Everyone on sets was quite skeptical about Katrina. But she amazed everyone as she comfortably climbed the ladder leaving Ranbir lagging behind. Ever since that day Katrina has always been addressed as Rambo’s sister Sambo by Ranbir,” said the source.