Tap the Apps icon located on the lower right corner of your Home screen.

Tap Internet (the browser will open up).

The menu options will appear, and you can scroll down to Settings.

From the settings option, select Privacy and Security. For more details you can visit Samsung India site.

You can enter unlock code using three following instructions:
1. Insert a  sim card (the sim card which is not supported by Your phone)
2. The phone should ask for an unlock code
3. Enter Unfreeze or Defreeze code ( unsuccesfull message may appear )
4. Enter NCK or Network code. I have also cheked another solution at Samsung … Read more