ALM only officially supports one character set at a time for the display of the actual headers and GUI information that the product uses to display menus and application related information and this was determined with the language pack that the application was installed with (most use the standard english package so it would be english, want another language and you would have to have installed with that particular lanuguage package and then only that language would be displayed). However if you have the DB coded to one of the multiple character sets encoding standards then you can get the entity information (the test case, requirement, and defect specific entity information within those entities) to be saved correctly and displayed within the program accordingly however the heading and program GUI will still be in the language pack that the system was installed with. In order for the character sets to display correctly the local user settings would need to support the language character set.
I would recommend that you get together with your technical support and open a case with them to address the issue as they can better assist you in this endeavor.
I hope this helps provide some clarification to your issue,