Help On Checking OverLaping in instantiating

Hello Everyone , I have a system that instantiate object where user click in the grid style of using

Mouthf.round(MousePos / TileSize.x ); and i change x to the value that i want and it works but i have a problem when i try to instantiate object bigger i can make him instantiate in grid with his right size and it places everything proberly but if the object is bigger it's overlap the another object , i want to make system that tell user that he can't place something here i hope that anyone can help . NOTE: i have box colliders on every instantiated object