Why Big B said no to Balayya, yes to Chiru?

Bollywood legend Amitabh Bachchan will be essaying an important role in Megastar Chiranjeevi's 'Sye Raa Narasimha Reddy'. This confirmation was made by the team yesterday when the first look motion teaser was launched.

But even before Chiru could rope Bachchan for his film, it was Nandamuri Balakrishna who approached Amitabh Bachchan. Balayya along with director Krishnavamsi went to Mumbai and requested Big B to do the role of Balayya's father in thier 'Rythu'. Big B then politely denied to be a part of this film. He cited callsheet issues.  This happened ten months ago and so far Amitabh Bachchan has not adjusted his dates for Balayya. 

Now we are wondering if  it was Big B's ploy to cite dates issue to politely say no to the film. There is also a news that he was not impressed with the storyline of Rythu. How else would you explain he agreeing to Megastar's movie? It has now become hot topic why Big B said no to Balayya and yes to Chiru?  Balakrishna also recently stated that he would not take up 'Rythu' if Big B doesn't accept the project. So, it seems the movie has been shelved with Big B preferring  Chiru's movie over Balakrishna's.