The Indian equity benchmarks gained for third day in a row on Tuesday on the back of buying interest in information technology heavyweights like HCL Technologies, Infosys, Wipro and Tata Consultancy Services (TCS) a day ahead of their December quarter earnings. The Sensex rose as much as 294 points and Nifty 50 index touched an intraday high of 18,081 and low of 17,964.