in
https://us.battle.net/
my country of residence is malaysia. In hover mouse on "?" says
My balance shows in USD however instead of MYR 
so you can register to https://us.battle.net

put in malaysian residence.

Or you can fake a US residence (though not sure if it will have any advantages)

Either way you can go on battlenet and select whichever region you want to play in e.g. americas/europe/asia

hope that helped 
I also recommend using authenticator in your security setup for login into your battlenet account. You can download the digital app for your android, or you can purchase the physical authenticator (which i have though honestly the digital works just as well).