Ponniyin Selvan" - Tamil historical novel written by Kalki Krishnamurthy.

You can buy the full episodes for a small fee following the URLs. 

https://awesound.com/a/ponniyin-selvan-audio-part-1-2

https://awesound.com/a/ponniyin-selvan-audio-part-2

https://awesound.com/a/ponniyin-selvan-audio-part-3

https://awesound.com/a/ponniyin-selvan-audio-part-4

Part - 5 - about to start

Other works:

https://www.amazon.in/dp/B08GM1XLSF

https://www.amazon.in/dp/1637540043?ref=myi_title_dp