The Foreign institutional investors (FIIs) were net sellers of Rs 252.52 crore in the futures & options segment on Thursday.According to data released by the NSE, FIIs were net sellers of index futures to the tune of Rs 264.74 crore and sold index options worth Rs 32.27 crore. They were net buyers of stock futures to the tune of Rs 26.94 crore and bought stock options worth Rs 17.54 crore.