If you want to block countries so that users located there cannot access your content, simply go to your account settings and click on 'Content Protection'. This allows you to hide your profile from specific countries or states/provinces individually. Also, keep in mind:

• By blocking countries, you will limit the reach of your account and, therefore, your fans.
• The blocking works by IP and, therefore, is not foolproof. Even if you block a country, a user might still see your content if they use a VPN, which would give them an IP address different from the country you have blocked.