In Kolkata, Nair picked Bengali actors like Tanusree Shankar and Supriya Devi to complete the cast for the The Namesake.
The maker of films like Mississippi Masala, Salaam Bombay and Kamasutra says she chose Lahiri's novel as her next film because she really identified with it.
"It so rightly catches the modern pulse of the South Asian culture in New York. The city's South Asian scene is really pulsating," she says.
The film doesn't depart too much from the book. "I haven't introduced any new characters. One of the changes is that Ashima is a fledgling singer because of my own love for music." she says.
"The film will have baul songs (folk music by roving minstrels of rural Bengal), Rabindra sangeet (Tagore's songs), bhatiali (boatmen's songs) and, of course, the great erudite culture of the Bengalis," she adds.
The $9.6 million film starts and ends with Ashima singing.
Photographs: Getty Images