[FBSession openActiveSessionWithReadPermissions:@[@"public_profile"] allowLoginUI:YES completionHandler:
     ^(FBSession *session, FBSessionState state, NSError *error) {
         // Call the sessionStateChanged:state:error method to handle session state changes
         [self sessionStateChanged:session state:state error:error];
     }];

// This method will handle ALL the session state changes in the app
- (void)sessionStateChanged:(FBSession *)session state:(FBSessionState) state error:(NSError     *)error
{
    // If the session was opened successfully
    if (!error && state == FBSessionStateOpen){
        NSLog(@"Session opened");
        if (FBSession.activeSession.isOpen) {

//            This is not working though I'm putting it as comment
//            [[FBRequest requestForMe] startWithCompletionHandler:
//             ^(FBRequestConnection *connection,
//               NSDictionary<FBGraphUser> *user,
//               NSError *error) {
//                 if (!error) {
//                     NSLog(@"User Info : %@",user);
//                 }
//             }];

        [[FBRequest requestForGraphPath:@"me"] startWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error) {
            NSLog(@"%@",result);
        }];
    }
    return;
}

{
    email = "email@domain";
    "first_name" = Hemang;
    gender = male;
    id = someId;
    "last_name" = Shah;
    link = "https://www.facebook.com/app_scoped_user_id/someId/";
    locale = "en_US";
    name = "Hemang Shah";
    timezone = "5.5";
    "updated_time" = "some date and time";
    verified = 1;
}