Hi Amit,
There is a page in the documentation that gives an example of a silent varfile, here:
https://techdocs.broadcom.com/us/en/ca-enterprise-software/intelligent-automation/release-automation-nolio/6-7/installation/install-servers-with-silent-installation.html
With that said, I find that it is usually helpful to install the application on the platform you intend on using, with the options you plan on using, let that complete and then copy the varfile available to you in the directory where you installed it.
I'll include some .varfiles that I use for NAC and NES across windows and linux.
Kind regards,
Gregg