The foreign institutional investors (FIIs) were net sellers to the tune of Rs 25.67 crore in the futures & option segment on Friday.According to data released to the NSE, FIIs were net buyers of index futures to the tune of Rs 129.78 crore while they bought index options worth Rs 82.45 crore. They were net sellers of stock futures to the tune of Rs 230.59 crore and they sold stock options worth Rs 7.31 crore.As per data available on the Sebi website - FIIs were net buyers of stocks worth Rs 67.60 crore in the cash market on Thursday. Domestic mutual funds (MFs) were net buyers of shares worth Rs 58.57 crore on the same day.