I forgot to mention the full context. It is Inkscape I am dealing with
https://gitlab.com/inkscape/inkscape
share/icons/hicolor is what I want to modify.
https://gitlab.com/inkscape/inkscape/-/blob/master/COPYING
These are their terms. But I am not good at understanding such terms. It will be a great help if you could tell me how I can deal with it. To be honest, I made it for personal use. But I don't mind sharing it as it looks good.
In short, I took a few icons from the Inkscape repo and has modified it. If I can label the appropriate license, I will put it in Github or Gitlab. Otherwise, I will keep it for myself. I do not want to be part of any legal hassle only because I tried to share my hardwork 🙂