Could somebody suggest me how to build an Internal Ring Gear please?
The same way you build a external gear. Make a involute shape mirror it connect it and repeat. Now if your not looking at a involute gear then it should be even more trivial.
Evolvent shapes are easy to do just move slanted and rotate on each iteration fo point creation.
Are there Plugins that do this kind of job
Possibly, real question is why would anybody make one, when its very easy to do it manually. And since its easy to do manually its also very easy to script.*
(when I worked as a mechanical engineer I did it once and all my other gears were just differently parametrized instances of that one construct. Nowadays engineers don't even bother with doing it once unless for some reason they work for a comppany that designs and perfects gears).
*scripting is much less work then writing a plugin. And as a general rule theres no point in writing a plugin to automate something that takes. But scripts do exist.