Bachchan plays a 102-year-old father to Rishi, who essays the role of his 75-year-old son.
The first poster of the movie is out on social media and it shows the megastar in a happy-go-lucky mood sporting a long grey beard with spectacles.
While Rishi appears grumpy in a grey moustache as he looks at Bachchan.
Rishi took to Twitter where he shared his picture with his "Amar Akbar Anthony" co-star.
"Wonderful to work again with the legendary Amitabh Bachchan. Thank you Amitji, it never felt the 26-years-old hiatus. We connected instantly!" Rishi wrote.
The film is based on the Gujarati play of the same name penned by Saumya Joshi.