Have a look at this article about using the clip and clip-path properties in CSS. In short, css clip is deprecates, but will work in just about any browser including IE. Clip-path is the newer way of accomplishing the same thing, but with some newer bells and whistles.
I've found it best to use a TweenMax.to tween to change these values. You could end up with your object flashing on and off briefly when the web page is first loaded if you use a TweenMax.from tween. In your scenario:
1. Use clip: rect(0px, 0px, 0px, 0px) in CSS to make your object "invisible" on page load
2. Use a TweenMax.to tween to change those properties
I also recently posted a thread about using the css clip to do exactly what you want; reveal and hide objects.