I have Surrounded a game Object with a rectangular Box and applied Physics properties to that Box so that load on the computation gets reduced. But i have a problem, whenever in animation if the Game objects body part goes out of the Box then it will not collide, Is there any solutions?
You can either change the size of your bounding box to encompass the entire object and all it's possible sizes (not very realistic). Or you can make multiple physics objects for the game object. The physics boxes would surround all the moving parts of the game object, and move with those parts in animations.