Each story has a story behind it. Each movie progresses in a different fashion and the end result is often different from the initial idea. So there is a similar talk regarding Rangasthalam among people closely associated with the mega compound.
It is being said that Allu Arjun is the inspiration or the person behind the story of Rangasthalam.
Well, the behind the scenes story goes like this... Apparently, Bunny liked some films from other languages. After watching them, he is said to have discussed the same with Sukumar and even suggested that it would be best if such a subject is approached with an old backdrop. After disclosing his thoughts, Bunny is said to have told Sukumar to develop a story.
Now to cut a long story short, one fine morning, Sukumar is said to have announced that he was doing the film with Ram Charan.
He is said to have told Allu Arjun that he was indeed inspired by his story idea and developed it further to make Rangasthalam with Charan.
Bunny is said to have merely laughed and congratulated Sukumar for the same. At least that's the story doing rounds in mega compound.
So in all, where Bunny suggested the idea for himself, the film went to Charan, thanks to Sukumar.