So here I am assuming, you downloaded the package to Downloads and then unzipped it there, i.e. you have 'Telemetry_v12.0_with_JRE' directory in your Downloads folder. And then you unzipped the mac.zip in the 'Telemetry_v12.0_with_JRE/bin' folder. If you downloaded to some other place, you have to replace in the text below the 'Downloads' to the directory name, where you unzipped the Tool install package.
Now open Terminal.
Type the following in Terminal the following commands:
cd Downloads
cd Telemetry_v12.0_with_JRE
bash runMac.sh
The Tool should now start.
If you get error "bash: runMac.sh: no such file or directory", it means your Telemetry Tool is not in the 'Downloads/Telemetry_v12.0_with_JRE' directory, but somewhere else.
If you get error about "bin/mac/bin/java: No such file or directory", then you have now unzipped the mac.zip to correct directory.
Cheers.