how to add support for Chinese, Traditional-Taiwan?

The system is definitely capable of handling simplified and traditional Chinese. Try re-creating this issue in a small test project to see if the problem is specific to your app or specific to how your adding localisation. Specifically:

1. Create a small test project with a base localisation of English.

2. Add Chinese (Simplified) and Chinese (Traditional) to it.

3. Fill out those localisations.

4. Run your app in both languages.

Note In step 3, you don't actually have to fill out the localisations correctly. Just add some dummy values so that you can tell which localisation you got.

If this test app works then you know that there's something weird going on with your main app. OTOH, if this test app doesn't work then either your localisation process has problems or there's something weird happening in the system.

Share and Enjoy
—
Quinn "The Eskimo!"
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

Thank you for the update

I have followed the steps that you mentioned but no joy.

Same problem exists with tes app also. Zh-Hant.lproj works fine for Chinese Traditional and Chinese Traditionl(Hongkong) but doesnot work for Chinese Traditionl(Taiwan).

If I rename Zh-Hant.lproj to Zh_TW.lproj, everything works fine. But Xcode doesnot provide any option to add Zh_TW.lproj.

I am using 10.10.4 and XCode 6.4.

Same problem exists with tes app also. Zh-Hant.lproj works fine for Chinese Traditional and Chinese Traditionl(Hongkong) but doesnot work for Chinese Traditionl(Taiwan).

Indeed. There seems to be some confusion about whether 'Chinese as used in Taiwan' should be

zh-TW

zh-Hant-TW

If I rename Zh-Hant.lproj to Zh_TW.lproj, everything works fine. But Xcode doesnot provide any option to add Zh_TW.lproj.

Indeed. It's OK to do this—historically it was necessary when dealing with localisations that Xcode didn't specifically understand—but it's clearly less than ideal.

You should file a bug about this. Honestly, I don't know enough about the history of Chinese localisations to tell you whether this is a bug in Xcode or a bug in OS X but, either way, something needs to be fixed.

And if you want a definitive answer about how best to work around this, I recommend that you open a DTS tech support incident for it. One of my colleagues—one who's more familiar with Chinese localisation—will then be able to help you on an official basis.

Share and Enjoy
—
Quinn "The Eskimo!"
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"