No country can actually ban Bitcoin. It is a global decentralized network, so no country can stop it.
However, they can make buying/selling Bitcoin with fiat money and accepting it by merchants illegal, which will make it very difficult and dangerous (you might go to jail for example) to trade crypto vs. fiat and use Bitcoin to buy stuff. This wouldn't destroy the Bitcoin network, but probobaly would have a great impact on its price as most people will probably not risk jail in order to trade and use crypto.