It shouldn't be a problem. Personally I have installed it many times. As you say, it is present in the RebornOS repository, so it would be enough to install it from there, or simply from the terminal, with a "sudo pacman -S google-chrome".
Could you tell me the type of error you get? So I could try to see what happens.
pamac has been updated. If you choose to install google-chrome, you would have to choose the existing option in our repository. If the build button appears, then this is the AUR version (you should choose the option that tells you to install). Here is an example with google-chrome-dev:
I apologize for the capture, which is in Spanish (which is my native language). There, where it says "Construir" it would be "Build", and where it says "Instalar" it would be "Install". As you can see, there are both options in the case of google-chrome-dev.