Perhaps your browser doesn't allow you to download Cisco RTMT from your CUCM | Application | Plugins link. I suspect this might be a standard setting in more security conscious locations.
Try this: https://your_CUCM_url_or_IP_address:8443/plugins/CcmServRtmtPlugin.exe
Now when you get it installed and it is visually unusable, check this bug out: https://quickview.cloudapps.cisco.com/quickview/bug/CSCva07316
- Right click your RTMT executable
- Click Compatibility tab
- Click Change High DPI Settings button
- Check Override high DPI scaling behavior.
- Choose System from dropdown
