You can set where your
site is targeted through Google's Webmaster Tools
1. Log into Webmaster tools
2. Click on your
site name
3. Click
Site Configuration
4. Click Settings
5. Click Geographic Target
6. Select your Target country
Although this setting can help as your website is in the public domain you cannot prevent your
site from being seen completely.
The difficulty is knowing which IP addresses relate to which countries. Then the list of addresses you would need to block would be vast. You would then need your website coded to specifically block those addresses. This isn't easy to do and if you found a technician able to do the work it would be costly, and potentially slow down your website.
We hope this is helpful,
Reason8 Support