Is the iPod touch 6g compatible with Vista?
I doubt the iPod itself will be the stumbling block, however, the minimum requirement for iTunes itself is now Windows 7, so you might struggle with anything new that will require authorisation or sync via iTunes. 

Ref: http://www.apple.com/uk/itunes/download/

On the other hand, this article has fixes for if you have difficulty with installation on Windows &amp; appears to cover Oses right back to XP - https://support.apple.com/en-gb/HT201668

So - I guess the first test will be to see if you can get iTunes 12 onto the computer.