You can do that by executing a JavaScript,
JavascriptExecutor js = (JavascriptExecutor)driver;
String response = (String) js.executeScript("return navigator.language || navigator.userLanguage;");
The above code will return the local language of the browser. From that, you can determine the country.
Further, if you want to check time zone, use this,
JavascriptExecutor js = (JavascriptExecutor)driver;
String response = (String) js.executeScript("return new Date().getTimezoneOffset();");
Hope that helps!