The Foreign Institutional Investors (FIIs) were net sellers to the tune of Rs 660.11 crore in the futures & options segment on Tuesday.According to data released by the NSE, FIIs were net sellers of index futures to the tune of Rs 238.32 crore and sold index options worth Rs 98.79 crore. They were net sellers of stock futures to the tune of Rs 322.96 crore and sold stock options worth Rs 0.04 crore.