Abhishek was the first to welcome his "Chintu Uncle" on board. He tweeted Thursday: "Crew show some major love to one of my all time favourites @chintskap Rishi Kapoor. Welcome to the chaos Chintu Uncle.Awesome to have u here (sic)"
The 62-year-old actor responded: "Thank you @juniorbachchan for the welcome. Happy to be here."
Here's what other celebrities shared through their Twitter handles:
Anupam Kher: "Welcome to the joy of Twitter @chintskap (Mr. Rishi Kapoor). Have fun Sir. Jai Ho.:)"
Karan Johar: "My most favourite actor and someone I have had the huge honor to work with...RISHI KAPOOR joins the Twitter family.... @chintskap"
Aditi Rao Hydari: "OMGOMGOMG... The most most amazing Rishi kapoor is on twitter!!! @chintskap...."
Kunal Kohli: "@chintskap welcome to Twitter sir. Tweeple Pls welcome my most fav actor & human being Mr. Rishi Kapoor to Twitter."
The "Bobby" and "Karz" star was recently seen in "Do Dooni Chaar" and "Student of the Year".