So the answer was quite easy. All I had to do was change the data type coming in to NSDictionary. Below is the correct code.
- (void)check:(NSDictionary *)json{
NSDictionary *json1 = [NSJSONSerialization
JSONObjectWithData:json
options:kNilOptions
error:nil];
NSUserDefaults *userdefaluts = [NSUserDefaults standardUserDefaults];
[userdefaluts setObject:[json1 objectForKey:@"Name"] forKey:@"name"];
[userdefaluts setObject:[json1 objectForKey:KEY_USER_ID] forKey:KEY_USER_ID];
NSLog(@"MainView - check - name: %@",[userdefaluts objectForKey:@"name"]);
NSLog(@"MainView - check - name: %@",[userdefaluts objectForKey:KEY_USER_ID]);
}