Try Below code in index.php of your public_html Root and change countries code and subdomain name as per your requirement
<?php
$user_country_code = $_SERVER["HTTP_CF_IPCOUNTRY"];
$site_subdomain = array_shift(explode(".",$_SERVER['HTTP_HOST']));
if ($user_country_code == "IN" && $site_subdomain != "india")
{
header( 'Location: http://india.domain.com');
}
else if ($user_country_code == "US" && $site_subdomain != "united-states")
{
header( 'Location: http://united-states.domain.com');
}
else if ($user_country_code != "IN" && $user_country_code != "US")
{
header( 'Location: http://domain.com');
}
else
{
// Do nothing
}
?>