A stock may be placed under surveillance for the Insolvency and Bankruptcy Code (IBC) if the company is facing financial distress, insolvency, or is unable to meet its financial obligations. The stock exchange places the stock under surveillance to monitor the trading activity and ensure that there is no market manipulation or insider trading. The stock may also be placed under surveillance if there are concerns about the company's ability to continue operating as a going concern. In such cases, the stock exchange may take necessary measures to safeguard the interests of investors and the integrity of the market.