It was widely reported that Rai Bachchan was lining up her first post-pregnancy role as Mrs de Winter in an Indian adaptation of Daphne du Maurier's Rebecca.
Speaking to The Times of India, Ratnam's wife Suhasini denied the reports, saying: "No, it's wrong. Mani is currently focused on Kadal, which still has seven days of shoot left. He will decide on his next only after this film releases.
"It will take him eight more months after that to write his next script. So, any news about his future project that comes up in this time period is false."
Rai Bachchan, who has not signed for any film projects since falling pregnant with her first child in 2011, shot her first post-pregnancy project for a jewellery brand.
The actress, who worked with Ratnam on her debut film Iruvar and later Guru and Raavan, has said that her priorities have changed since becoming a mother.