Hi Durba, I'm Toms Varghese a colleague of your friend Vidhi Upadhyay. This story was written by me and it was based on an interview with Kailash Kher. He said that talks are on with Rahman and if things work out fine, the maestro would sing for him. But, nothing has been finalised yet. http://www.dnaindia.com/report.asp?newsid=1135950 you can read the story from this link.
Regards
