To put custom custom tattoos, please see this tutorial : https://forum.fivem.net/t/release-tutorial-add-new-tattoos-and-overlays-example-included/8450 . After, edit the list.lua . First, add in "tattoosCategories" the name of the categorie and then the name of the collection (name of your xml). After, add your tattoos in the "tattoosList" like the others.
Also, you can re-release this script for ES and other cores. But I ask you to credit me.