Yes, it's a real story. The novel Ponniyin Selvan, on which various adaptations are made, is deeply rooted in the history of the Chola empire. It weaves together the tales of kings, princes, and the political and social milieu of that era. There are historical records and research that support the authenticity of the overall backdrop against which the story unfolds. It gives us a glimpse into the grandeur and complexity of the Chola civilization.
Yes, it is. Ponniyin Selvan is a fictionalized account of real historical happenings in the Chola dynasty. The story incorporates real places, such as Thanjavur which was an important center in the Chola kingdom. The characters in the story, while having fictional elements in their personalities and personal stories, are also representative of the types of people who would have existed during that time in the Chola hierarchy, like the valiant warriors, the shrewd ministers, and the noble royalty.