Will the weight of gas measurement in space as well as in other planets of the Solar system be different as compared to gas measurement on Planet Earth?
Weight is a property of mass which you can experience only when on the solid surface of a gravitating body - but not when you are in free fall. Yet even in free fall you retain your mass. Weight is the force the mass exerts on a scale (in the presence of and proportional to the strenght of a gravity field which pushes the mass onto that scale - which requires that neither is in free fall).
Mass itself is the fundamental property of any particle itself - independent of how much other mass is in its vicinity, thus independent of external gravity field around.
See also the wikipedia article on the distinction of mass and weight.