Hi Shokan, typically it is difficult to do kind of finer detailed bumpy "relief" type designs with MoI.
One method that can be used is to build the basic broad shape with MoI and then take that into a displacement-brush based software like ZBrush or 3D Coat, to apply the relief details there.
There are also some different modeling programs that are more specifically focused on making relief designs, like ArtCAM may be worth checking out for doing that.
