Reuters Market Eye - The BSE Sensex and the Nifty gain around 2 percent, after Brent crude dropped more than $2 a barrel following a breakthrough nuclear deal between world powers and Iran over the weekend.
Falling oil prices could help contain inflation and narrow India's current account deficit given the country imports crude for most of its needs, traders say.
Shares of state-run oil marketing companies gain: Indian Oil Corp gains 2.9 percent, Hindustan Petroleum Corp surges 5.7 percent and Bharat Petroleum Corp is up 4.4 percent.
Top Sensex gainers are: ICICI Bank up 5 percent, SBI gains 3.7 percent.
Axis Bank Ltd gains 3.6 percent after exchange operator BSE Ltd said it will include the lender in its benchmark BSE Sensex starting on December 23.