Ranbir and Alia, who are Ayan's close friends, truncated their vacation to attend the funeral.
Jaya Bachchan, who was one of the first to arrive, was seen hugging Kajol who was Deb Mukherjee's niece.
Filmmakers Ashutosh Gowariker, Karan Johar, screenwriter Salim Khan, Bollywood star Hrithik Roshan were among the attendees.
Mukherjee was also the father-in-law of eminent filmmaker Ashutosh Gowariker.
Deb Mukherjee, who was also a veteran Indian actor, passed away at the age of 83 on Friday.
Mukherjee passed away at around 9:30 am after he was hospitalised. He was suffering from age-related health issues.
Born in Kanpur, Uttar Pradesh, Mukherjee is known for films like Karate, Jo Jeeta Wohi Sikandar, King Uncle.
His last film was Vishal Bhardwaj's Kaminey, a Shahid Kapoor and Priyanka Chopra starrer flick released in 2009.
Ayan is the son from Mukherjee's second marriage.