To make it more simple and understandable. If your country bans bitcoin then you won't be able to exchange it into cash if you needed the money for something unless you'll do it in between your friends or someone you know but if you get caught doing this, I guess there would be sanctions since it is not legalized in your country. Anything that is not legalized in your country is punishable by law if you'll be caught doing transactions that your government doesn't approve of it so better just hold your coins until the time will come that it will be legalized by your country.