"I received several calls from several producers (post 'Dostana')... But everyone in the industry knows my loyalty to Karan is too strong. No amount of money or fame can buy that, " Mansukhani told in an e-mail interview.
"Karan gave me freedom to make the film I wanted... with no pressures of budgets and market expectations and for that I'm eternally grateful, " he added.
Mansukhani plans to stick with the 37-year-old filmmaker.
"It's been 12 years in films now... and all those years have been spent in one institution, in one family - the Johars. And they've always taught me to dream big. And I have.
"But what surprises me every now and then is Karan. He seems to have bigger dreams for me than I have for myself. So I hope both our dreams come true... and we can continue to make films together till our sanity remains, " said Mansukhani, who started his career as an assistant director to Karan for "Kuch Kuch Hota Hai" (1998).
In "Kabhi Khushi Kabhie Gham" (2001) and "Kabhi Alvida Naa Kehna" (2006) Mashukhani worked as first assistant director. He credits the success of his comical hit to Karan.
"The only reason that 'Dostana' happened, got the buzz, the opening, the reaction was because it was a film presented by Karan Johar. That name stands for quality wholesome entertainment. And that name backs me. There's nothing more thunderous than that, " he said.
The 33-year-old admits that he is in awe of his mentor.
"Karan is amazingly clear about his films. He is aware of its strengths, its weaknesses and its requirements. He lives, eats and breathes his film... and whilst doing that he manages to be stylish, entertaining and business-minded.
"He knows his job and more often than not, he knows other people's jobs as well... but just like his father (Yash), he never blames, yells or puts anyone down. No matter how many mistakes one makes, he always corrects them and pushes one further..."
"I know I'm making him sound too good to be true... but the truth is he is. And yes... I'm in awe of him, " he explained.
Noteworthy is that despite being major successes abroad, most of Karan's films have been tagged by critics as "plastic cinema" courtesy the superficiality of its entire set-up and narrative and larger-than-life lavishness.
But Mansukhani doesn't agree with the critics.
"There is no set norm for the films we make. We at Dharma are just doing our job, just like the critics are. It's our job to make films we are proud of and think an audience would enjoy watching.
"It's critics' job to see those films and give their opinion on the film so that an audience can decide whether they want to see the film. The critics might call our films plastic... but, hey, everyone seems to like plastic, " he remarked.
Mansukhani's future projects includes animation film "Koochie Koochie Hota Hain" with voice-overs from Shah Rukh Khan, Kajol and Rani Mukerji and a sequel to "Dostana" - both with Dharma Productions.