Equity benchmark indices witnessed a volatile trading session after a steady start on Friday amid lack of positive triggers. Sensex witnessed over 660 points intraday fall and Nifty 50 declined nearly 190 points. Sensex traded 191.44 points or 0.23 per cent lower at 84,213.02 at 1.05 pm, and Nifty 50 dropped by 66.65 points or 0.26 per cent to 25,811.20.Both the midcap and smallcap indices ended the session on a flat note. Among sectoral indices, most traded in negative territory, with notable weakness in m ...