The Foreign Institutional Investors (FIIs) were net sellers to the tune of Rs 728.98 crore in the futures & options segment on Monday.According to data released by the NSE, FIIs were net buyers of index futures to the tune of Rs 716.51 crore and bought index options worth Rs 348.08 crore. They were net sellers of stock futures to the tune of Rs 1,762.35 crore and sold stock options worth Rs 31.22 crore.