If there isn't a path in the url just append .eg to the end of the string.
NSString *newCountryString = [[url absoluteString] stringByAppendingString:@".eg"];
NSURL *newCountryUrl = [NSURL URLWithString:newCountryString];
If the url has a path do this:
NSString *host = [url host];
NSString *domain = [[host componentsSeparatedByString:@"."] lastObject];
NSString *newCountryString = [[url absoluteString] stringByReplacingOccurrencesOfString:domain withString:[domain stringByAppendingString:@".eg"]];
NSURL *newCountryUrl = [NSURL URLWithString:newCountryString];