Regional Language setting from English (US) to English (Australia) change via GPO Preference

Anyone please assist.

That should work. Have you tested it?

I just wanted to check am whether I am in right direction/path, OR is there any setting that ensures, it changes the language setting to English (Australia)

That setting will change it for all users that apply that policy.

Thanks for that. Please advise why the location setting is greyed out to United States. Will this affect? Please advise.

That can't be changed through preferences because it's a computer setting and not a user setting.
See: http://technet.microsoft.com/en-us/library/cc754020.aspx

You could change it by modifying the registry: http://blogs.technet.com/b/askperf/archive/2012/08/16/how-to-change-regional-settings-for-all-users-on-a-computer.aspx

Have a look at this one to update your Language Settings via GPO

https://www.experts-exchange.com/questions/25277115/Using-GPO-to-change-Keyboard-Language.html

Applied the Group Policy preference, its not getting applied, the regional language settings is  still set to Eng (United States)

Where are you applying the policy? To an OU? Are there user objects in the OU or sub OU? Can you run a gpresult to see if the policy is getting applied or not?

Attached are the screenshots on the settings that I have applied and the scope of the policy. I am not sure why the policy is not getting applied.

Please advise.
GPO-Scope.PNG
Preferences-setting.PNG

Are the users in the XenDesktop OU? If not then that is why the settings are not being applied, since they are user settings and not computer settings.

Any authenticated user who logs on to one of the XenDesktop located in XenDesktop OU will get this policy applied.

So you are saying that the users are in the OU or is loopback processing configured?

Users are not in that OU - scope is being set as you can see in the screenshots that I have provided that - Any authenticated user who logs on to one of the XenDesktop located in XenDesktop OU will get this policy applied.

I am not sure why this is not getting applied as I have other User policies in the same GPO that are getting applied no issues.

I am starting to think is there a way that you can change regional language settings via Registry setting using GPO. Please advise.

That is not how group policy processing works. The sco

Can you please elaborate?

Yes, sorry, was responding from my phone and accidentally hit submit.

So the scope is the OU and the security filtering is the Authenticated users. So if you want to limit the scope, you can use security filtering to do that. (you can also use WMI filtering but that isn't relevant here)

You can have the User Configuration apply to users based on the policies that computer applies if you configure Loopback processing in the Computer Configuration

More info:
Group Policy Processing - http://technet.microsoft.com/en-us/library/cc785665(v=ws.10).aspx
Security Filtering - http://technet.microsoft.com/en-us/library/cc781988(v=ws.10).aspx
Loopback Processing - http://blogs.technet.com/b/askds/archive/2013/02/08/circle-back-to-loopback.aspx

I am Citrix admin, Sorry I am not an GPO expert, what is the way out to ensure that this gets applied. My AD admin is saying that the scope is correctly defined as illustrated in screenshot.

He is now asking if I have any registry setting for this change. Please advise.