A few simple steps to follow to make wheel rim. The steps can be followed both in Catia and Solidworks in a similar way.
Make a sketch as shown in any plane.
Exit the sketch. Rotate it around the center line as shown.
You will get somethings similar to this.
Now create a plane as shown in the figure .
Sketch a drawing similar to that of the sketch shown in the figure. You can go for complicated shapes as per your requirement. For simplicity, for now the shape is kept simple.
Pocket the sketch.
Use "circular pattern" to pattern this hole all around as shown in figure. Be sure to select the "complete crown" option for equal space between the holes.
Your wheel rim is ready. Following similar processes you can be able to make many complicated rims very easily. The steps are similar both in Catia and Solidworks. Hope this is helpful to you. :)