Auto Scaling of Gameobjects

In general, the screen is considered a 'viewport' into the game world. As such, stretching the gameobjects to match the viewport does not make sense except under very special circumstances. Can you explain in more detail exactly what you are trying to do?

@ syclamoth-- I want rescale plane (3D object ) for 1024 x 768 and 960 x 640 and 1136 x 640 pixels.

try Transform.localScale

Your question is confusing. Your camera's field of view (or orthographic size) deter$$anonymous$$es how much is seen by the camera. Vertical screen resolution does not change what is seen vertically. Horizontally, your game can grow or shrink to accommodate the changing aspect ratio. There are times when you want change the size of game objects (for example if you wanted things pixel perfect on multiple devices), but I'm not getting the sense that is what is going on here. Note you can change the camera's field of view ins$$anonymous$$d of changing the sizes of the individual game objects.

I will second what robertbu said above. Changing the camera viewport is a lot better idea than changing the size of all objects,which can incur unnecessary overhead on the cpu especially if you are using mobile devices.