Your old windows plug-ins will not work on your new macintosh.
You need to find/download mac versions of those plug-ins.
Additionally:
About Macintosh Plug-ins
There is much confusion when it comes to Macintosh VST/VSTi due to the history of the platform.
Up until 2006 all Macintosh were built using PowerPC processors. If you have a G4 or G5 then you have a PowerPC. Nowadays, all Macintosh computers are built using Intel x86 processors.
A lot of old Plug-ins were made before 2006 and never updated. These plug-ins are known as PowerPC specific. These old plug-ins will only work on a G4 or a G5. They will not work on newer Intel Macs.
Universal binary Plug-ins are compiled in a special way which allow them to operate on both PowerPC and Intel Macs. The symbol used to indicate this feature is the Yin-Yang. These types of plug-ins work on all Macs.
As PowerPC dies out, Macintosh Plug-ins are expected to become Intel Only. These newer Plug-ins will not work on PowerPC machines.
Lastly
There are caveats when using multiple operating systems and 3rd party plug-ins and instruments (VST).
The same plug-in on Mac or Windows or Linux might not use the same parameters (or even have the same naming conventions) from one OS to an other. Different versions of the same plug-in on the same OS tend to also do this.