The Foreign Institutional Investors (FIIs) were net sellers to the tune of Rs 961.72 crore in the futures & option segment on Thursday.According to data released by the NSE, FIIs were net sellers of index futures to the tune of Rs 1,576.46 crore while bought index options worth Rs 1,238.55 crore. They were net sellers of stock futures to the tune of Rs 626.67 crore while bought stock options worth Rs 2.86 crore.As per data available on the Sebi website - FIIs were net sellers of stocks worth Rs 59.20 crore in the cash market on Wednesday. Mutual funds were net buyers of shares worth Rs 51.60 crore on the same day.