You can use the steps in this article to install Apple Remote Desktop Admin when the installer reports that it requires Mac OS X v10.6.
Follow these steps to install Apple Remote Desktop and update it to a version compatible with Lion or later.
Use the instructions below to install a compatible version of Apple Remote Desktop Admin on the OS X version you are using.
OS X Yosemite
First, update to OS X Yosemite 10.10.2 or later. Then use the Updates pane of the Mac App Store to update to Remote Desktop 3.8 or later.
After updating, Remote Desktop appears in your list of Mac App Store purchases. You can install it on other computers that meet system requirements by logging into the Mac App Store using your Apple ID.
OS X Mavericks and earlier
Use Software Update to update to the latest version of Apple Remote Desktop compatible with your version of OS X.