Ranbir Kapoor and Vicky Kaushal are really caught up these days. The two, who play Sanjay Dutt and his bestie respectively in the actor's biopic, have not only been shooting for the film in and around the city, but have also been preparing for something rather special at a suburban dance studio.

The duo has been rehearsing discreetly for a medley of Dutt's hits, which we hear, will be used in his biopic, to show appreciation for his work over the years. One of the key numbers in the medley is the title track of Khalnayak. The rehearsals began sometime in April and have continued over the last one month. “The song hasn't been shot yet. They have only been rehearsing because the idea is to complete the scenes first,“ says a source close to the project.