You can check TNAU website (
TNAU Agritech Portal :: Home ) for the crops that suit the season. To start with, go for standard crops like Tomato, Onion, Brinjal, Ladies Finger etc which are used daily in cooking. Since you have a large land holding, just start with 1 or 2 acres to begin with and then expand rapidly in the next season.
Read articles related to Organic farming and that is enough to understand. BTW, if you want to learn more and you are okay to spend a little bit money & time for learning organic farming, go to Vanagam for training (
https://www.facebook.com/pages/Dr-G-Nammalvar-Organic-Agriculturist/197789246939878). Check when is the next batch here.
BTW, as of now I am only a Farming Enthusiast and I help people through different medium like internet, in-person etc. I don't own land currently and in the process of acquiring land.
Regards
Padmanabhan Ganesan
Agriculture for Everybody