Here's the best kept secret in La-La Land. Aditi Rao, the scene-stealing actress from Rakeysh Omprakash Mehra's Delhi 6, is the parallel female lead opposite Ranbir Kapoor in Rockstar.Initially Aditi was summoned to play the leading lady opposite Ranbir, but the part finally went to half Czech and half Pakistani Nargis Fakhri."I was called to meet Imtiaz sir for the other part (Nargis Fakhri). But he had already set his mind on Nargis, signed her and started training with her. She was training for many months," said Aditi, who also features in Sudhir Mishra`s Yeh Saali Zindagi.Luckily Aditi and Nargis have no scenes together in Rockstar."I`m happy with the part I finally got in Rockstar. I am the narrator who connects Ranbir's character to the audience. It's a part like Rani Mukerji's in Veer-Zaara. I play a young journalist. The chemistry between me and Ranbir is… well, you will have to see it yourself," she said.Apparently Aditi has powerful scenes, but the film's publicity will be designed to spotlight the Ranbir-Fakhri pairing. Hence, the orchestrated stories of a real-life relationship between the hot new pair."Trust me, these rumours of Nargis and Ranbir will die down the day Rockstar releases. Poor Aditi. She has a very important role in Rockstar. But she is married and just not fodder for gossip," said a female co-star of Ranbir.