Brokers said buying activity gathered momentum as investors opened their books on the first session of Samvat 2076. Major gainers in the Sensex pack were Tata Motors, Yes Bank, Infosys, Vedanta Ltd, ITC Ltd, Hero MotoCorp, HDFC Bank, Tata Steel and RIL, rallying up to 16.07 per cent. However, Bharti Airtel, TCS, HUL, Maruti and PowerGrid slipped up to 1.86 percent.