Gaurav, who is currently in South Africa shooting for the crime thriller, plays a small role in the film but he is excited about the project because most of his scenes are with leads actors DiCaprio, Jennifer Connelly and Djimon Hounsou, the Daily News reported.
Gaurav said director Edward Zwick ("The Last Samurai", "I Am Sam" and "Traffic") was "happy to have him" but felt the former was perhaps a little too good-looking for the part. Hence the character, which was of a French journalist, had to be rewritten for an Indian.
"It is a huge production and, with everything planned right down to the minute detail, changing one thing has a domino effect. So I do appreciate the fact that they had rewritten the characterisation for me.
"The actual work that happens on set is at such a high-end professional level. While everyone there is very experienced, it is a question of how suitable you are for the role," he added.
Gaurav, who started his career as a model, acted in serials like "Saara Aakash" and "Dil Kya Chahta Hai".
"The Blood Diamond" is a crime-thriller and revolves around a farmer, a smuggler and a syndicate of businessmen who match wits over the possession of a priceless diamond.
Gaurav has become popular in South Africa since he played the lead role in the Durban-based theatre and film director Junaid Ahmed's West End-styled Bollywood-themed musical "Bombay Crush".
"'Bombay Crush' has opened doors for me and I am going to use the exposure in the right way. Basically, I am saying I will be around for lots of other things, from television roles to event shows."