I am not able to hide particular part of 3D model and animation play particular time(0.45).
I'm afraid the Wikitude JS API supports neither of these two things.
By "hiding a particular part" I assume you mean to hide one of the sub-meshes of your model only. To work around the lack of this feature you could use two separate AR.Models instead of one. One for the part you wish to hide separately and one for the rest.
Starting an animation at a specific time is, I'm afraid, not possible either. You could, however, have a separate animation in your FBX/WT3 file that represents the animation started at a time of .45.