Hi I am trying to take one chair(fbx) in prefab and i used them at runtime but when i am giving some setting for that prefab like rotation it changes at scene level but at runtime it is same as previous one please help me
When you drag a prefab to your scene view and do some changes, that will not change the original prefab unless you hit the Apply button in the inspector at the top right corner.
Or you have an alternative method, you drag your new(modified) prefab on to your original prefab (found in project view).
Note that the prefab found in the project view is like having a class , and dragging a copy to the scene view represents creating an instance of a class.
If this was not the answer you wanted, please give more details about your question.