Sebi and stock exchanges have beefed up their surveillance mechanism to deal with any excessive volatility in the run up to the 'Brexit' referendum whose outcome is keenly awaited by the investors. Ahead of the referendum, stocks and rupee saw sharp fall in afternoon trade today with benchmark 30-share Sensex falling nearly 200 points. The domestic capital market has a robust surveillance and risk management framework in place and it has been beefed up to deal with any eventuality emanating from the 'Brexit' referendum, a senior official said. All steps are being taken to ring fence the capital market from any adverse fallout as well as ensure that excessive volatility is contained, he added. The United Kingdom will vote tomorrow on whether to remain in or leave the 28-nation European Union. Britain's exit from the bloc, widely described as 'Brexit', is being debated globally as such a development could have far reaching implications for the international financial markets, exchange rates and the world economy as a whole. There are also fears that exit of Britain from the EU could trigger significant capital outflows, including from the Indian market. According to the official, Sebi and the bourses would also keep a close tab on manipulators looking to exploit the volatile trends expected in stocks and derivatives, including those linked to rupee's movement against other foreign currencies. A strict vigil would also be kept on brokers, portfolio managers and other market intermediaries for any attempts to lure small retail investors into promises of hefty gains from the futures and options trading, especially in banking stocks and indices, the official added. The Reserve Bank of India (RBI) today said it is keeping a "close vigil" on developments and would also take all necessary steps including liquidity support to ensure orderly conditions in the financial markets. "In the run up to the referendum in the United Kingdom on its continuing in the European Union ('Brexit'), uncertainty about the poll outcome has resulted in some amount of turbulence in global financial markets, including in India," RBI said in a statement. "The RBI is maintaining a close vigil on developments, and will take all necessary steps, including liquidity support, to ensure orderly conditions in financial markets," it added. In early afternoon trade, Sensex declined nearly 200 points before recovering amid concerns over 'Brexit' referendum and BJP leader Subramanian Swamy demanding the sacking of Chief Economic Adviser Arvind Subramanian.