The movie released Friday, and it is being lauded for being an entertainer with a purpose.
"In 'PK', I play the head of a news channel and it is important in the film because it's a news network that covers most of what happens in the life of the character PK, after a certain point in film," Boman told IANS.
"I know I'm working in a film ('PK'), which will have some great social impact on this country...cinematic impact, social impact...social change," he said.
Boman also pointed out at how all of Hirani's films, like "Munna Bhai M.B.B.S.", "Lage Raho Munna Bhai" and "3 Idiots", have been about social change.
"(They offer a) different way of thinking, modern in a traditional sense...I enjoyed every single moment working with him (Hirani) and I would had done anything in the film and he knows it.
"'PK' is a very special film for me and I'm happy to have done it. It's not the biggest role, in fact it is the smallest role, but that shouldn't matter ever," he added about the film, which also stars Aamir Khan, Anushka Sharma, Sushant Singh Rajput and Sanjay Dutt.
Talking about his bonding with Hirani, Boman said: "I think it's a lot to do with the fact that both of us started our careers together. My first Hindi feature film was 'Munna Bhai M.B.B.S.', and so was his. The thing is that we travelled that journey together, as two people who were trying to find a place within the industry at that point of time in 2002.
"We make it a point that twice a year, just two of us take off (somewhere), and we have kept that little custom of ours going for a long time and we speak about everything about life, friendship, family, relationship, story, ideas, character. It's a great relationship that I cherish A lot and I think he does too."