Dear mohdfaheem,

basically all versions of RayMan are available free of charge. However, the "Pro" version is mainly a development version. There is only few differences between the versions 1.2 and "Pro" (see other threads in this forum).

If you still want the "Pro" version, please contact Prof. Matzarakis and ask for a download link. However, for most studies, you won't need it.

Best regards,
Dominik