Why Did Sanjay Dutt Ask for an Extension for Pk?

Sanjay Dutt had made a plea requesting for an extension before undergoing the  remaining sentence, as much of his movies were pending,one of the movie named to be completed was PK, in which he stars with Aamir Khan. Recently someone revealed a stunning news.

According to sources,”Sanju’s portions were already shot a while back over three days at the CST station in Mumbai. He is no longer required for the shoot. Raju’s film has wrapped up. Where is the question of Sanjay shooting for it during the extension?”

So why did Sanju mention PK as one of his pending films and sought extension before undergoing the remaining sentence in the 1993 Mumbai blasts case?