I solved it myself.You have to set its completion using following code.
Just add following code after presenting controller
[controllerSLC setCompletionHandler:^
(SLComposeViewControllerResult result) {
[[NSNotificationCenter defaultCenter]postNotificationName:@"hideNotification" object:nil];
NSString *output = [[NSString alloc] init];
switch (result) {
case SLComposeViewControllerResultCancelled:
output = @"Post Cancelled";
break;
case SLComposeViewControllerResultDone:
output = @"Posted successfully";
break;
default:
break;
}
}];