There are no special requirements to run the utility on your Solaris machines. All you need to do is to purchase a Solaris license from the official web page. Click the VNC button, select Enterprise, type a number of computers and users click Continue and follow the on-screen instructions. Once you purchase the license, you can download the program from the Download center and install it using the serial key.
If you already have a Windows version, you can try installing it on your Solaris machines using Wine. Wine is a free of charge program that helps you run Windows applications on Linux, BSD, Solaris and Mac OS X.