Bitcoin can not be banned because it is part of a decentralized system. This decentralized system allows Bitcoin to be an unregulated platform that can not be banned or controlled. So it's just your choice if you want to invest in Bitcoin, and no one can stop you and can not destroy the currency on the market.
However, the government may decide whether or not cryptocurrency may be used as a means of payment in that country. But that does not prevent us from investing in our favorite crypto coins.