Hi @MaheshKPati ,
The behavior you are observing is expected and by design. When creating a language copy of a page in AEM, the target language dropdown in the Create Language Copy dialog only displays the languages that are defined in the Language Copy Configuration for the site. If the language code present under the existing language-master is not available in the target language dropdown, it means that the language is not defined in the Language Copy Configuration for the site.
To create a Language Copy of a page for a language code that is not defined in the Language Copy Configuration, you can follow these steps:
1. Go to the Language Copy Configuration for the site. This can be accessed via the Site Administration console.
2. Add the language code that you want to create a Language Copy for to the Language Copy Configuration. This will make the language available in the target language dropdown in the Create Language Copy dialog.
3. Go to the page that you want to create a Language Copy for and select Create > Language Copy from the toolbar.
4. In the Create Language Copy dialog, select the target language from the dropdown. The language code that you added to the Language Copy Configuration should now be available in the dropdown.
5. Complete the remaining fields in the Create Language Copy dialog and click Create.
This should create a Language Copy of the page for the language code that you added to the Language Copy Configuration.
It's important to note that adding a language to the Language Copy Configuration will create a new language root node in the repository for that language. This can impact the structure of your content tree and may require additional configuration and customization. It's recommended to consult with experienced AEM developers or solution architects before making changes to the Language Copy Configuration or content tree structure.