The standard installer has support only for English, but you can download separate language packs and spell check dictionaries separately after installation.
The TortoiseSVN user interface has been translated into many different languages, so you may be able to download a language pack to suit your needs. You can find the language packs on our translation status page. And if there is no language pack available, why not join the team and submit your own translation ;-)
Each language pack is packaged as a
.msi installer. Just run the install program and follow the instructions. After the installation finishes, the translation will be available.
The documentation has also been translated into several different languages. You can download translated manuals from the support page on our website.