Stocks to buy: HAL, Mphasis and Infosys on investors' radar

Stock markets experienced a sharp decline on Tuesday with Sensex plunging by 1,390 points. Key stocks in focus included HAL, Mphasis, and Infosys, with experts recommending a 'buy on dips' strategy for HAL, a no-trade zone for Mphasis until a clear trend is established, and a 'sell on rise' approach for Infosys.