Bachchan, 72, who plays a hypochondriac father, took to Twitter to thank his fans.
Amitabh Bachchan tweeted:
T 1862 – Pranaam, Namaskaar and greetings for the affection shown towards PIKU … pic.twitter.com/WXyNgXnfZh
— Amitabh Bachchan (@SrBachchan) May 11, 2015
Set in Delhi and Kolkata, the road drama also stars Deepika Padukone, Irrfan Khan and Moushumi Chatterjee.
The Shoojit Sircar-directed film hit theatres last Friday and has been recieving a good box-office response.