The Foreign Institutional Investors (FIIs) were net sellers to the tune of Rs 326.77 crore in the futures & options segment on Thursday.According to data released by the NSE, FIIs were net buyers of index futures to the tune of Rs 611.60 crore and bought index options worth Rs 279.72 crore. They were net sellers of stock futures to the tune of Rs 1,220.25 crore and bought stock options worth Rs 2.16 crore.