Nifty is approaching towards the key resistance zone of 10,630-10,645; as previously this zone had offered strong resistance to the index and led to the decline in the index. Top stocks to watch out today: Simbhaoli Sugars, PNB, Jain Irrigation Systems, Mahindra and Mahindra, ACC, HDFC Bank, Sagar Cement and Indiabulls Real Estate.