Yadav announced the government's decision before the media at his official residence, and said he watched the film Tuesday night.
He said the film "was a very nice one" and urged the media persons to go and watch it.
Yadav criticised people and organisations for protesting against the film, saying they were doing it without any valid reason.
He said the protesters would also laud the film's story after they watch it.
"I regret not watching the film earlier as I was busy with other engagements," he said.
The Bharatiya Janata Party hit out at Yadav, and said he was trying to incite certain groups by his announcement.
"Any government should try and douse protests. Here, the chief minister himself is becoming a party to the controversy," BJP state spokesman Vijay Bahadur Pathak told IANS.
He said that when some Hindu groups were opposing the film for hurting Hindu sentiments, the chief minister should have avoided the decision.
Some groups Wednesday protested against the tax free status to "PK" in Lucknow, Rae Bareli and Kanpur.
