Ammyy (or AMMYY Admin) by Polat Bilgisayar is a freeware tool that allows you to remotely access computers from any location (with the access to the Internet, of course). You won't be able to find Ammyy for Mac, but you can try other applications that will help you remotely access your system. Here are some programs that can serve as a replacement for Ammyy for Mac
Feel free to add any alternative to Ammyy for Mac that you know of.
Suggest Alternatives
R-HUB remote support servers seem to be available only for PC.
You may add R-HUB remote support servers to the above list. It is an on premise solution which works from behind the firewall.
The best alternatives here are TeamViewer and Chrome Remote. But as Chrome is a greedy RAM hog, I'd stick to TeamViewer.