Hi VJ,
Below is the splunk link to download heavy forwarder on Mac.
https://www.splunk.com/en_us/download/splunk-enterprise.html
This is the link which gives you some instructions on HF installation.
https://docs.splunk.com/Documentation/Splunk/7.1.1/Forwarding/Deployaheavyforwarder
Let me know if this helps.