Enable SMS count on galaxy s3 lock screen?
Hey man you can use this.
Notification LockScreen Widget (available for free in the Google Play store).
It gives following features. 


View all dismissible notifications including missed calls, SMS, Facebook notifications, Gmail, etc.
Launch the app directly from the notifications list.
Combine multiple similar notifications into one notification with
counter.
Allow full original notification content as it appears on
notifications bar.