Bootable Osx USB on windows 10

No not obvious ;-[

If you've got an old macOS install image, it will probably stop working today Apple re-released Sierra, High Sierra & Mojave installers.

You also have a systems who’s OS is not supported any more as El Capitan OS-X 10.11.6 is the newest this system can support.

Here we need to use a different approach as the certificate test leverages the systems date setting held. So we need to alter the systems settings so the installer thinks it’s years ago! So using the Installer to boot up the system go into the preferences and alter the the date setting to 2017.

Reference:

How to make a bootable OS X 10.11 El Capitan installer drive. You’ll need to get the Installer file from the App Store from another older Mac that can gain access to it or find someone with it.

As far as using TransMac - Its a bit tricky! Most people can’t get it to work setting up the installer USB drive. You also need to format the thumb drive with GUID and a journaled file system replacing the FAT32 format.