You can enable additional languages in Microsoft Dynamics CRM by installing language packs. You can use this feature to display text in different languages in the user interface, Help, and reports. For more information about how to install a language pack
To categorize a report by language, use the Report.languagecode property. You can set this property to a specific locale ID (for example, 1033 for U.S. English) to display the report to users who use that language. For example, an off-the-shelf English Customer Summary report appears in the reports table in the English user interface, but the report is not displayed in the same organization's Spanish or German user interface.
The Language element in a report Definition language (RDL) file does not determine where the report appears in Microsoft Dynamics CRM. It contains expressions that are used to calculate the language code defined in the Internet Engineering Task Force (IETF) RFC1766 specification. Language codes are primarily used to format numbers, dates, and times in a specified language
CRM uses different languages to categorize and display reports