"I think only Dhanush can become 'Raanjhanaa'. He has got the innocence. I think there is nobody who has that spirit that is as clean (as his) over here (Bollywood)," said the 27-year-old in an interview.
"There is a lot of innocence and at the same time there is a lot of love in the way he approaches everything," added the actress who has worked with stars like Ranbir Kapoor, Abhishek Bachchan, Imran Khan and Shahid Kapoor in the last six years.
Directed by Anand L. Rai, "Raanjhanaa" also features Abhay Deol who had earlier worked with Sonam in "Aisha".
Slated to release June 21, "Raanjhanaa" is a love story of a Hindu boy who falls in love with a Muslim girl.