There are 2 types of Ban,
If the open interest of the stock reaches the certain higher point(95%) the exchange will ban the stock until its reaches the specified lower open interest point(80%). In this case there will be no impact on stock price.
There are lot of criteria like Liquidity , Market Cap ect., will be considered by exchange before adding the securities into F&O. If the script is not able to full fill any of the criteria the stock will be excluded from F&O permanently. If the ban is due to some mismanagement of the company like satyam the ban will leads to decrease in stock price.(but not always).