When you apply for a VPS we ask you what OS you want out of the ones that we offer, i.e. Debian/Ubuntu/CentOS/Fedoror/Suse. When you get a VPS you also get access to a Virtualizor Control panel through which you will be able to reload the OS out of the ones that are on offer in the panel. I.e. Debian/Ubuntu/CentOS/Fedoror/Suse. Kali Linux is not included as our VPSs aren't designed to do what people do with Kali Linux - the VPSs are for lighter use, mostly web development and light VPS applications. If you're an avid Kali user, our VPSs may not be suitable for the applications you want to use it with.