Bollywood producer Vashu Bhagnani negotiated for months to buy the exclusive rights to remake Psy's "Gangnam Style" for use in his latest film, Rangrezz.

The process was not easy, or cheap.

The movie, which stars the producer's son Jackky Bhagnani, uses Psy's song for the opening credits.

The film's director, Priyadarshan, was initially not happy about including "Gangnam Style" in the film stating he did not think it fit in with the serious themes of the movie, but eventually came around to the idea.

"Initially, I felt the "Gangnam Style" track didn't fit into Rangrezz. You have to understand this is not one of my lighter films. Rangrezz is not a comedy. And there's no way an item number can be interpolated into the plot," said Priyadarshan. "But then Vashu Bhagnani and I had discussions over the song. We both agreed finally that the film needed a big promotional track," he added.

And before Psy would sell away "Gangnam Style" for Bollywood consumption, he also had some stipulations.

For starters, the filmmakers were not allowed to make any changes to the song, it needed to stay in its original form.

Also, before he would accept the offer, Psy needed Jackky to prove his dancing abilities. The actor reportedly performed the "Party Abhi Baaki Hai" song from another Hindi film titled F.A.L.T.U. in front of Psy before the paperwork was finalized.

One source said, "Psy didn't want to pass on the song to incapable hands...or feet. If it was going to be used in a Hindi film, he wanted to make sure the dancer knew what he was doing."

Vashu Bhagnani agreed and added, "Getting the song was not easy at all. There was a constant back-and-forth of email for weeks. They had innumerable questions about how we would use the song. Yes, they did want to see who would be dancing to the number before giving us the rights."

While Bhagnani has not revealed exactly how much he paid for the rights to the song, some sources have suggested it was upwards of about 50 million Rupees (approximately $1million).

Another Hindi producer told ZeeNews India he was also interested in buying the rights to "Gangnam Style" but said the price was out of his range. "I was very keen to get the song myself. Then I heard Vashuji was negotiating, and the price he was willing to pay way exceeded my budget," said the producer. He added, " At that price, I could record three original 'Gangnam' songs right here in India."

Rangrezz opened in India on Friday.  You can watch the official trailer below.