Will the SMS software package (Tortoise Redmine Plugin x64) work well with Windows 10?
I don't think Windows 10 is an issue here since it's a plug-in for another application. You just have to make sure that Tortoise SVN is compatible with Windows 10, then you can follow the installation instructions from the page listed below.
According to system requirements, Tortoise SVN is compatible with Windows Vista or higher on both 32 and 64bit architecture version.