If you are using Arduino CLI directly or Arduino IDE 2.x instead of Arduino IDE 1.x, ctags is installed in the builtin package under the "Arduino15" folder. For example, on Windows it will be something like this:
It seems that Arduino's version is based on the latest release of exuberant ctags. From a quick look at its sourceforge, it does appear that there has been some work upstream since that release.
They did mention that they would like to switch to "universal" in the issue I linked above.