The Foreign Institutional Investors (FIIs) were net sellers to the tune of Rs 1,347.57 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 965.75 crore while bought index options worth Rs 95.90 crore. They were net sellers of stock futures to the tune of Rs 471.69 crore and sold stock options worth Rs 6.03 crore.As per data available on the Sebi website - FIIs were net buyers of stocks worth Rs 446 crore in the cash market on Wednesday. Mutual funds were net buyers of shares worth Rs 16.20 crore on the same day.