There’s an interesting section on docs.microsoft.com about: How to build a localization for Business Central. If you are planning to build localization apps, you should pay attention to the following considerations and requirements:
f you are a NAV customer based in Bulgaria, Croatia, Estonia, Indonesia, Latvia, Lithuania, Malaysia, Philippines, Romania, Serbia, Singapore, Slovakia, Slovenia, Thailand, or Turkey, or if you are planning to deploy NAV in one of these 15 countries, this is a reminder to you that Microsoft will no longer be providing your country localizations or language translations from April 1, 2013.
Recently I was asked to help with localization of Dynamics NAV for Korea. I was involved a couple of years ago with another project that we implemented in Korea and so I knew the process on how to localize NAV classic client. The project was on version 4.0 sp3. Microsoft has not localized NAV for any country in Asia, except India.