He passed away in Singapore after travelling there for a kidney transplant.
Kanwar is most famous for launching the career of Shah Rukh Khan in 1992 with the film Deewana. The actor led the tributes on Twitter, writing: "My friend Raj Kanwarji passed away. The impermanence of life, makes one feel so helpless. May his soul rest in peace. Aisi Deewangi... miss u sir."
The director also signed up Lara Dutta and Priyanka Chopra for their first Bollywood endeavour, 2003's Andaaz.
"Saddens me so much, my first director Raj Kanwar passed away..RIP Rajji..You believed in me when even I didn't. Andaaz taught me everything I know," Chopra tweeted.
Actor Abhishek Bachchan said: "Terribly saddened by the passing of Raj Kanwar. Was the first person to sign me after Refugee. He made Aishwarya and my 1st film together. Dhai Akshar Prem Ke.
"Was a lovely man, always happy, smiling and joking. Have wonderful wonderful memories of him. Now no more. Thank you so much Raj ji for the memories. I will miss you."
