The good news is that you have many better, safer options to use MestReNova for free or at a low cost.
Using a cracked version of MestReNova is a clear violation of copyright law and the software's End User License Agreement (EULA). Distributing or downloading a crack is a form of software piracy. While individual users are rarely the target of large lawsuits, universities and research institutions take this very seriously. If you are caught using cracked software on a university computer or network, you could face serious disciplinary action, including the loss of your network privileges, academic penalties, or even termination of employment. Furthermore, publishing research that was analyzed with pirated software can compromise the integrity and ethical standing of your work.