Posting a picture of the legendary actor from "Mera Naam Joker" on his Twitter profile, Rishi wrote on @chintskap: "Happy birthday dad! We shall always remember you.......love!"
The tweet got 590 retweets and 11.4K likes.
Fans posted black-and-white pictures of the Bollywood great as also wrote lyrics of evergreen songs from his hit movies over the decades. There were also clippings and photographs of Raj Kapoor with his family members.
Bollywood actor Amit Sadh wrote on @TheAmitSadh: "Remembering my favourite legend Raj Kapoor Saab on his 95th birth anniversary. He made what we are a part of, we walk his craft and his art. He will be cherished forever...."
"He was the best human being. And a superstar," a fan replied to Rishi Kapoor.
Another fan wrote: "Remembering the greatest showman on his birth anniversarya."
One post read: "Tribute to Raj Kapoor sir, legendary actor and director on his birth anniversary."
One fan posted a sepia-tinted picture of the actor-director with his mother. "Remembering Raj Kapoor sahab on his birth anniversary!!! Herea's absolutely the rare pic of Raj sahab with his mother wishing him a very happy birthday on December 14, 1959. "
A user commented: "Remembering one of the most genius filmmakers on his birth anniversary. You are and will continue to be an inspiration for generations to come & will always remain alive in our hearts."
Raj Kapoor was born on December 14, 1924, in Peshawar to actor Prithviraj Kapoor and his wife. He died on June 2, 1988, in Delhi.
( With inputs from IANS )