Yes, Nim v1 is a garbage collected language. It also shipped with custom destructors support https://nim-lang.github.io/Nim/destructors.html.
Nim v2, which is hopefully two releases away, will ship with a memory management scheme called "orc" https://nim-lang.org/blog/2020/12/08/introducing-orc.html
However right now, it is recommended that all new code is written with the `--gc:orc` switch.