The Foreign Institutional Investors (FIIs) were net sellers to the tune of Rs 342.57 crore in the futures & option segment on Tuesday.According to data released by the NSE, FIIs were net buyers of index futures to the tune of Rs 30.74 crore and bought index options worth Rs 140.62 crore. They were net sellers of stock futures to the tune of Rs 510.31 crore and sold stock options worth Rs 3.61 crore.As per data available on the Sebi website - FIIs were net buyers of stocks worth Rs 319.80 crore in the cash market on Monday. Mutual funds were net sellers of shares worth Rs 54.23 crore on the same day.