Indian benchmark indices ended Tuesday's session almost flat, but with a slight negative tone, as gains in PSU banks, metal and auto stocks were offset by selling pressure in IT, FMCG, realty and pharma shares. Sensex ended at 84,675.08, down 20.46 points (0.02%), while Nifty closed at 25,938.85, down 3.25 points (0.01%).