Sujoy Ghosh's thriller Kahaani stars Vidya Balan and Parambrata Chatterjee in lead roles.
"Not too much, but as per the script, Vidya will have few action scenes in the film. So as the script demands, I had asked her to be in shape. There will be some physical activities that Vidya will have to do in the film," he added.
Kahaani, shot in Kolkata, came in he beginning of 2012 and was a super hit. The film revolved around Vidya's character, who was in search of her missing husband.
Now Ghosh is working on the script of the second instalment, which will repeat characters from the original.
"The script is not yet ready. We are in the process of developing the script. Once the script is ready, the film will go on the floors next year," he said.
"Few portions will be shot in Kolkata and many of the characters will be repeated," he added.