Pulavar Karthick Raja Pillai
13 days
My theory :
Chera - Bhil,
Chola - Koli,
Pandya - Mina tribes
After defeated by Parashuram Aryan Army, they would have been replaced entirely by Aryan Kshatriyas, then Sangam age starts with Tolkappiyam
At 300 AD, Cholas, Pandyas replaced by Kalabhras (Karalar or Vratyas)