There are two types of distrbutions.
- Region Exclusive
Most region-selective events cannot be obtained from any other regions. So events exclusive to USA, Europe and Japan will most probably never happen in Burma. Such events include GameStop corner distributions and many tournament giveaways.
In short, you will most probably never get these Pokemon through the direct distribution, you'll have to trade for it from people who already have it.
However, those events that are not region exclusive i.e Wi-Fi events can be obtained from the Internet. Here's a rough procedure as to how to obtain one during a distribution:
- Make sure that your console is near a Wi-Fi and is connected to it, and open your game.
- When you see your screen (the very first one) you have the option of "Mystery Gift". All distributions happen through this.
- The event will be specifying as to how you obtain your Pokemon, whether through Internet or Code or whatever. The screen will show you the options, and choose the one specified.
- Receive your Pokemon through the method! Now you should have the event Pokemon successfully.
- Lastly save your game.
Hope I helped!