Official Translations for JomSocial can be found here
Jomsocial Language Packs
Jomsocial language translation packs can be downloaded as installable Joomla packages. Please note: this page is updated every 7 days and files with less than 25% translated are not included in the packs
Install your preferred Joomla language pack using the Joomla language manager and set it as the default site language
Install your Jomsocial language pack following the steps below
Click on the language you would like to install on your site
Click on the download now button on the right and save the zip file to your preferred location
Login to your joomla administrator panel and select extensions > extension manager
Continue with the standard Joomla component installation process
Your Jomsocial installation will now use the new language pack