Reuters Market Eye - NSE's volatility gauge, India VIX surges 7.3 percent.
Heads towards fourth day of gains in five on fears of foreign investor sales.
Has risen nearly 20 percent since Sept. 22.
Foreign investors sold shares worth 11.33 billion rupees ($185.31 million) on Friday - NSE.
Overseas investors sold shares in each of the three sessions till Friday to a total of $337.9 million - CDSL
Their biggest selling streak since May.
Traders cite uncertainties including the Supreme Court's cancellation of most coal blocks allotted since 1993.
State elections in October also seen weighing.
(Reporting by Abhishek Vishnoi)
