The Foreign Institutional Investors (FIIs) were net buyers to the tune of Rs 603.21 crore in the futures & option segment on Wednesday.According to data released by the NSE, FIIs were net sellers of index futures to the tune of Rs 395.51 crore while bought index options worth Rs 652.49 crore. They were net buyers of stock futures to the tune of Rs 343.80 crore and bought stock options worth Rs 2.43 crore.As per data available on the Sebi website - FIIs were net sellers of stocks worth Rs 415.70 crore in the cash market on Tuesday. Mutual funds were net buyers of shares worth Rs 348.58 crore on the same day.