A large majority of all websites have content that's only relevant to a country or region. This can be problematic because visitors from other countries or regions may not exactly be visiting your site with your best interests in mind.
This module allows you to set to read-only or completely ban visitors based on individual IP addresses or by country (using IP address lookup).
For complete bans, you can redirect the user to any page you choose and/or display an "error" message. There is nothing preventing you from entering an external address as the page to redirect to.