Asia->thailand region locks?

If you bought it on Steam, it's region locked and can only be redeemed in Thailand and several SEA countries such as Indonesia, Malaysia, Philippines, or Singapore.

To my knowledge, most games are but you might want to re-confirm it by checking on steam database.

Edit: Keep in my mind that I'm talking about Steam here. I don't know if other websites have region locking. You would have to check with the vendor in question.