South.. Which is your South. Karnataka, Kerala and AP are well within India. They will not and never thought of leaving India. Think of your TN without any non-Tamils (their investment) please include your much hated Brahmins (they are not Tamils ..cause your TVS group and others, their schools, IIT) will all leave. They will be happy in Bangalore or Hyd (great cosmopolitan cities to live). Now think of your State.. You will be left with Ramdoss, lots of MK, FYI., open your eyes and see how many of the IT companies are owned by the group I listed above. The answer is clear as your city's exclusive hot daylight. You need more .. I have more to give you. Don't pelt stones from a glass chamber..
