If you want a Pokemon with 6 max IV's, then breeding is your best option. Of course, since this is Ditto, then it can't breed and create itself, so never mind.
The chance of finding a Pokemon with 6 perfect IV's in the wild are so small that I personally wouldn't bother with it. But then I'm an impatient guy. I've spent the last few days searching for a Ditto with an Adamant nature, and have practically given up by now, and that's just trying to find a certain nature, which is much easier to get than perfect IV's. To give you an idea of how hard it is to get a Pokemon with flawless IV's through breeding (which like I said is a lot easier than in the wild), then look at the source below. If both parents have 5 perfect IV's, then the chance of the offspring can run anywhere from 1/59916 to 1/140734, depending on exactly which stats are perfect in the parents. This was written before the release of X and Y, though, so I'm betting the new use of the Destiny Knot has vastly improved these stats. However, the fact remains that even through breeding (pre-X and Y) you are not likely to get a Pokemon with perfect IV's. And of course it is even harder in the wild.
So, in short, I would suggest giving up your quest for the perfect Ditto (which I'm assuming you intended to use for breeding anyway).
Source for breeding for perfect IV's