Sensex tanks 256 pts, Nifty ends at 7762; Coal India up 3%

Sensex tanks 256 pts, Nifty ends at 7762; Coal India up 3% Coal India, Bharti, Axis Bank, GAIL and Tata Steel were top gainers while Vedanta, Cipla, Bajaj Auto, ONGC and Hindalco were losers in the Sensex