I Would Like to know If Virual DJ Can Be Used On PlayIt
Not really Andrew, no.
Virtual DJ is similar software (but for a different market).
The key difference is that PlayIt Live's strength is playing a pre-programmed schedule of songs whereas Virtual DJ (and similar programmes such as Mixxx) are really intended for "performance" mixing of music.
It would be possible to take a stream (or audio) from Virtual DJ and play it on PlayIt Live but there is no obvious reason to want to do so.