please is there any way to import a video in unity 3D without having unity3D pro version ? 
Strictly speaking, no. But if it is a small video then there are some video texture assets on the store. Usually one would have to extract the images from the video file and import them as stills into the video texture asset for Unity free and playback that way. That is only really feasible with small videos.
There is also an AVI player available on the asset store. It states it can be used for Unity and Unity Pro, it looks like the streaming features are Pro only, still you would need to check with the developer as it wouldn’t be the first asset which is wrongly advertised.