The Indian stock market witnessed a rally on Thursday with the BSE Sensex gaining over 600 points.The rally was fuelled by a 7 per cent rise in Reliance Industries’ shares. RIL stocks touched a record high of Rs 2,343.9 and its market capitalisation is currently over Rs 14.67 lakh crore.The surge in share prices comes on the back of the announcement of Rs 7,500 crore investment by Silver Lake into Reliance Retail Ventures Ltd, an RIL subsidiary.