Is there any way to use rocscience software on a mac. I tried Paralells, but it won't let me activvate the software on a VM

A lot of proprietary software that uses a license for activation will require the software to be running on bare metal and not on a VM. The more a vendor locks down their software the more restrictive its use becomes. You may have no choice but to install the software directly without any VM. You can check with the developer to see whether they allow their software to be used within a VM and if so how it can be done. I personally stay away from software that has very restrictive licenses for activation as those types of apps/developers end up being an absolute pain because you need to contact them for almost everything especially if you ever need to move the software to another computer for any reason (sometimes they won't let you do it without buying another license).