Indian equity indices opened a tad lower on Tuesday as heavyweights like L&T and Bajaj Finance were trading in the red. At 9:24 am, Sensex was down 152 points or 0.19 per cent at 81,221.39 and Nifty was down 36.40 points or 0.16 per cent at 24,680.40. Buying was seen in the midcap and smallcap stocks.