Ranbir joked that Katrina would often say it was she who helped him deliver two superhit films- 'Ajab Prem Ki Gajab Kahaani' and 'Rajneeti'.
"So, I thought when I become a producer I will be grateful and pay back and I will make a film for her. Dada (director Anurag Basu) and I have made Jagga Jasoos only for Katrina.
"She is amazing in the film, she is unbelievable. This is going to be Katrina Kaifs best performance."
Ranbir, who is reuniting with Katrina for the third time in "Jagga Jasoos", said the actress achievements have been unbelievable.
"She is a machine of superhit films, every film she does is a superhit. We also used to joke that she should just touch our film so that it becomes superhit. I dont feel there has been a greater star than Katrina in the film industry."
Ranbir on Friday launched the "Galti Se Mistake" song from the film.
On making mistakes in his life, the actor said, "I dont think there are any mistakes in life, there are only learnings in life as that is how you grow."
Talking about his character in the film, Ranbir said, "The film is more of a father-son relationship and how my character becomes a jasoos and he meets Shruti (Katrina)."
When asked about the qualities that he imbibes from his father, Ranbir joked, "not to drink".
"The kind of love and values that are family gives us is important. They have done lot of things for us and now I am their parent I am make sure I give them all the joy and happiness."
"Jagga Jasoos" also marks the reunion of Ranbir and Basu after "Barfi".
"I dont think he (Anurag Basu) can work with any other actor as I understand his process. I dont want him to work with another actor because he is the finest director of our country he has great knowledge about cinema, performance, music.
"When we had planned Jagga Jasoos we had also thought of a sequel. It has been an amazing experience working with him."