For which planets Kepler has formulated his laws? Kepler has formulated his three laws of planetary motion around the Sun.

Did he formulate the laws for all 9 planets or only for a part of them? Say I do not know if all the planets have been discovered at the time.

 A: Kepler found his laws by calculating from the differences between the orbits of Earth and Mars. Because of he amount of calculation, and because he employed no assistant, he did not calculate other orbits. Finding that an elliptical orbit fit the Mars data, he immediately concluded that all planets move in ellipses, with the sun at one focus—Kepler's first law of planetary motion. Actually he was fortunate in Mars, because its orbit has a greater eccentricity than most of the others, and probably could not have obtained a result from the available data for any other planet. I think he chose it because it had the most complete data set from Tyho de Brahe's observation. Mercury has greater eccentricity, but he was uncertain of the data, and had he discovered the precession of the perihelion, he probably would have rejected elliptical motions!
Other astronomers tested his ideas for other planets, but it took a while for his laws to become generally accepted, probably only after Newton published the Principia.
A: he formulated them for the known planets, up to Saturn, Uranus, Neptun, Pluto were not discovered but he knew the would apply to any.
