I haven't looked at the EA, but networksetup is on my Mac (10.13.3):

Mac:~ dave$ which networksetup

/usr/sbin/networksetup

Might be that the EA has a typo or is looking in the wrong location.

Looks like that message is coming from the EA

else
echo "<result>The networksetup binary is not present on this machine.</result>"

Could you post a copy of the EA code?

sure its the one from the templates in JSS

!/bin/sh

OS=/usr/bin/sw_vers -productVersion | /usr/bin/colrm 5
if [[ "$OS" < "10.5" ]]; then
if [ -f /System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/networksetup ];then
NetworkInterface=/System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/networksetup -listnetworkserviceorder 2>&1 | grep $(/usr/sbin/netstat -rn 2>&1 | /usr/bin/grep -m 1 'default' | /usr/bin/awk '{ print $6 }') | sed -e "s/.Port: //g" -e "s/,.//g"
echo "<result>/System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/networksetup -getdnsservers "$NetworkInterface" 2>&1</result>"
else
echo "<result>The networksetup binary is not present on this machine.</result>"
fi
else
NetworkInterface=/usr/sbin/networksetup -listnetworkserviceorder 2>&1 | grep $(/usr/sbin/netstat -rn 2>&1 | /usr/bin/grep -m 1 'default' | /usr/bin/awk '{ print $6 }') | sed -e "s/.Port: //g" -e "s/,.//g"
echo "<result>/usr/sbin/networksetup -getdnsservers "$NetworkInterface" 2>&1</result>"
fi

A lot of the template EAs are quite old, and sometimes broken unfortunately.

It looks like the above EA is it's looking inside the ARDAgent.app for networksetup if the OS is lower than 10.5. I'm guessing in your case you're not running 10.5, in which case, the script is failing to read the OS correctly.

I would edit the code to remove that part.