The Rajkumar Hirani-directed film, which raises questions about religion and people's blind faith in godmen, was released in December 2014. It was co-produced by Vidhu Vinod Chopra and Hirani.
Justice Najmi Waziri sought response from Hirani, Chopra and scriptwriter Abhijat Joshi by September 1.
Isapuri has alleged that certain portions from his Hindi novel "Farishta", published in 2013, were "stolen and copied" and used in the film.
He also sought punitive damages of Rs.1 crore from the filmmakers along with credit for his work.
However, counsel appearing for filmmakers contended that as per the custom and practice of Hindi film industry, the script of the movie was first registered with the Writers Association in Mumbai on July 29, 2010.
Earlier, the title of PK was Ghar Jaana Hai, told the counsel, adding that later five revised versions of the script were submitted with the association and final version of the script was registered in 2012 having title PK.
On the other hand, advocate Jyotika Kalra alleged that the makers of the film as well as scriptwriter Joshi stole characters, ideas and sequences from the novel "Farishta".
Kalra argued that the first manuscript of the novel was submitted to a publication house in October 2009 and the novel was first came into public domain in 2013.