Nifty traded at 24,846 in Tuesday's expiry session, with Sensex at 81,066. Tech led gains as Infosys jumped 4% on buyback news, while autos slipped. RailTel surged 5% on an order win and Voltamp fell 3% after promoter stake sale. Analysts flagged volatility ahead of expiry, with resistance at 24,950 and support near 24,700.