I'm the founder of company, which buy the stocks of US Company. My company registerd in Georgia (Not state of USA, but country). Which form I must fill for Taxation?

If your stockbroker is in Georgia, for sure you have NO filing requirement for the U.S.

Now, if you use a stockbroker in the United States, then it is likely no tax is owed, though that ultimately depends on the tax treaty between the U.S. and your home country, which you failed to mention (the fact that your company is registered in Georgia does NOT necessarily mean you live in Georgia).