Bollywood actress Sonam Kapoor has opted out of Mani Ratnam's new Tamil film which will be the debut of Karthik's son Gautham. 

But why did Sonam Kapoor decide on not doing the movie with someone like Mani Ratnam? "At this point in her career going Southwards for Sonam would give the wrong signal to the filmmakers in Bollywood. Mani had his heart set on Sonam since she suited the young innocent effervescent sophisticated girl's role to the hilt. He had to look for a last-minute replacement," said a source.

The role has now gone to actress Samantha Ruth Prabhu who will be making her Bollywood debut with 'Assi Nabey Poore Sau'.