When you reach your destination country, switch on your mobile phone, and it should automatically select an operator.

If you cannot find an operator, please check the configuration in your mobile phone under network settings. Your phone may be set-up to select the network manually. Switch it to automatic network selection mode, and it should find a roaming network for you.                                                                                                                                          

For information on stc's Roaming packages, visit https://www.stc.com.bh/content/data-roaming-add-ons-0.