The Foreign Institutional Investors (FIIs) were net sellers to the tune of Rs 350.97 crore in the futures & option segment on Tuesday.According to data released by the NSE, FIIs were net sellers of index futures to the tune of Rs 354.90 crore while bought index options worth Rs 66.65 crore. They were net sellers of stock futures to the tune of Rs 61.15 crore and sold stock options worth Rs 1.57 crore.