PSU stocks were hit hard by the stock market crash as shares of RVNL, IRFC, Mazagon Dock and NBCC fell up to 8 per cent today. Indian Railway Finance Corporation Ltd and IRCON International Ltd were down 7 percent each, RailTel Corporation plunged nearly 7 per cent and Mazagon Dock Shipbuilders fell over 6.5 per cent. Defence PSU stocks including …