Ranbir is going through a rough patch in his career as his last few films -- "Besharam", "Roy" and "Bombay Velvet" failed to grab eyeballs.
"His movies not doing well is a sad thing. But he gives his heart and soul for a film. I know it hurts and pains him deeply that maybe he is not able to live up to the expectations and satisfy his audience," Katrina told PTI.
"He loves his audience... he wants people to love his films... he wants that acceptance from audience. So all this is hurtful to him," she said.
The 32-year-old actress is hopeful that Ranbir will bounce back.
"But as an actor, I haven't seen anyone more passionate and focused about his work. It is just a matter of time. Every actor goes through ups and downs. I am sure with his passion, dedication and God's blessing, things will change," she said.
Talking about her recently-released film "Phantom", Katrina says she is happy with the audience's response. The actress is now excited for Nitya Mehra's film with Sidharth Malhotra, for which she has started shooting. The film titled "Baar Baar Dekho" is a love story, which happens over a period of time.
"Nitya's film is an amazing love story. It is an idea that shocked me when I first heard it. I have not seen or heard a film like this in long time," she said.
"Most of the love stories are of similar types, but this seemed new and exciting. There is lot of performance in it," she said.
Sidharth had earlier revealed that they would go for prosthetics look for the film.
Talking about it, Katrina says, "It (use of prosthetics look) is there for a small portion in a film. Like in "Barfi" when they (Ranbir and Priyanka) are growing old and dying so you won't say it is a film using prosthetics."
"It is used in a small portion in the film. There is a very small portion (growing old) that comes towards the end of the film," she said.
Excel Entertainment and Dharma Production's are collaborating with Eros International for "Baar Baar Dekho" and it marks the directorial debut of Nitya. It will release in 2016.
Katrina's upcoming films include "Jagga Jasoos" and "Fitoor".