Original: Mentions of the political situation of Tamil Nadu before the common era are found in Asoka's edicts dated c 300 BCE and, vaguely, in the Hathigumpha inscription dated c.150 BCE.
Simplified: Mentions of the political situation of Tamil Nadu prior to the common era are found in Asoka's edicts dated c300 BCE  and the vague mention in the Hathigumpha inscription dated c.150 BCE.