I'm not so sure - historically only people from the US , UK, Canada & Australia seem to have made it in. I don't blame them - being from one of these places significantly simplifies the whole visa stuff.
Depending on how your company is formed could make a big difference. Keep in mind that YC is investing $10-20K in your company, so it may not be appealing if there are $40K in legal costs to create an entity that they could invest in.