Bachchan, who is always on time for press conferences, marriage or other events, was late by almost an hour-and-half.
"I am extremely sorry for coming late. I started from home by 10 AM but I got stuck in traffic for one-and-half-hour. I apologise for coming late," Bachchan told reporters here at Filmcity in suburban Mumbai.
Big B was scheduled to arrive for the event at 11 AM, but reached by 12.30 PM.
The 69-year-old actor even sent an apology message to the PR team for making the media wait.
The sixth edition of popular game show KBC will go on air from September 7 on Sony Entertainment Channel, on Friday, Saturday and Sunday.