Ramya Krishna got to play those roles because Aishwarya Rai and Sridevi didn't do them. We are talking about her iconic characters, Neelambari from Narasimha and Sivagami from Baahubali.
Neelambari was first offered to Aishwarya Rai, then known for being a former beauty queen. She turned down the role. Ramya Krishna was not even the second option in the minds of Rajinikanth and director KS Ravi Kumar. Sridevi and Madhuri Dixit were considered. All three actress who turned down the film had a pan-Indian image. Ramya Krishna, who was a star heroine but not as big a superstar as the other three, was offered the role at the behest of the director.
Sivagami was first offered to Sridevi. As per Rajamouli and producer Shobu Yarlagadda, she made unfair demands concerning her remuneration and the five-star treatment for her entourage. Sridevi's husband, Boney Kapoor, later denied making such a demand, though. He accused Shobu of cooking up a story since Rajamouli was not present during those discussions. Whatever it is, the character was destined to be played by Ramya Krishna.
