"As you watched the trailer, he (the character) is a frustrated man," said Mr Bachchan who was accompanied by the film's director R Balki and co-actors, Tamil superstar Dhanush and debutante Akshara Haasan.
The Shamitabh team is in Ahmedabad for a promotional event of the film, scheduled to release on February 6. When asked about his experience of working with R Balki, Big B said, "An actor only follows instructions."
"No work is easier in life. People may think that one feels good in front of camera. I have been working in the film industry for many years. Sometimes there remains a fear that what is cameraman thinking of, what is the demand of the script and whether I will fulfil or not," he added.
Mr Bachchan said he had done many films with R Balki and the latter is like his family member. "But when camera starts rolling, we forget mother, father, brother or friends, we only remain actor and feel the character. Whatever has been instructed, we do that," he said.
When asked about his son, actor Abhishek Bachchan once again turning a producer, the he said, "People have their own thinking, Abhishek had earlier produced films (Paa) and he is also doing acting apart from producing films."
Some parts of Shamitabh were shot in Seven Hills Hospital in Mumbai where Mr Bachchan had undergone an abdominal surgery earlier. "Balki insisted to shoot in the same hospital to add element of reality," he added. In the content of the film, Mr Bachchan parried the question by quoting lines from the trailer, "It is not picture, it is mixture."
R Balki said Shamitabh is a story of two egos who clash with one another. "It is the story of two egos of how two people clash and nobody can be successful indeed. Most people think they can do it alone, most people think they have done it all. It is not like that. Behind every successful person, there is a team," said R Balki, who had earlier directed movies like Paa and Cheeni Kum with Mr Bachchan.
Dhanush, whose song Kolaveri Di had become a cult and who had earlier worked in Bollywood movie Raanjhanaa, said the story of Shamitabh is unique and very fresh.
"I am deeply honoured to work with Amitji," he added. The younger daughter of actors Kamal Haasan and Sarika, Akshara, who is making her Bollywood debut with the film, said it was a magical experience to work with stars like Mr Bachchan, Dhanush, and R Balki.
Mr Bachchan also praised Akshara. "This is Akshara's first film. I have a special family relation with her. She is daughter of Sarika and Kamal Haasan and obviously, she got the talent in her genes," he said.