Given the following circumstances, how can I jailbreak my iPhone 6+
There is currently no way to jailbreak (as far as I know) using a virtual machine

Instead here is what i recommend you do (source):


  Download bootra1n 0.10.1
  
  Download Rufus, press SELECT, open the ISO file, and press START to flash it to your USB drive.
  
  Reboot your computer and enter your BIOS's boot menu.
  
  
  Select the flash drive, and it should boot into the login prompt
  Log in as anon, with password voidlinux
  At the $ prompt, enter sudo checkra1n
  


Further information can be found here