The dates of Ramayana and Mahabharata have been confirmed by archeology, Astronomy, Paleantology, Literary references from foreign sources, Anthropology, archeoanthropology and Simulated software with inputs from these Indian texts and correlating them with Astronomical events.
Mahabharatha alone has 39 cities validated.
,as Vasishta left along with Shiva at the time of Tsunami there are minimal references to Vasishta in the South.
By the time they returned to india, and Vasishta had become the Kula Guru of Ikshvaku Dynasty, years had gone by.
In the south the other progeny of Shiva, Subrahmanya, called as Murugan in Tamil spread Santana Dharma in South East Asia and developed the Santana dharma further in the south.
That is the reason one finds the Murugan is identified with Tamil and Shiva being treated as the Adhi Siddha and as ‘Ancient of the Ancients’
Munnaip Pazhamporutku Munnaip ParamPorule – Tamil.
This implies that The Tamils were in existence in Treta Yuga itself as Muchukunda was alive then.
The ancestor and the funder of Lord Rama’s Dynasty,Ikshvahu name means ‘Sugarcane’
As I have posted earlier Ikshvahu’s ancestor, Satyavrata Manu,also called Vaivasvatha Manu,migrated from the South,Tamil Nadu with his sons to the North.
The Dravidas , people of the South,knew the cultivation of Sugarcane.
There is a mention of this in Tamil Poet,Avvayar’s poem on King Adhiyaman .