water is somewhat ok, but not too realistic. and the floor is just like a cartoon, I used a texture for the displacement map as well for the rock floor but still cartoon like 
, I’m using V-ray exterior default preset as the settings.
where to find good photo realistic materials to be used with vray?
At least you got the displacement part right.
I think the water alone looks fine. It is what is around it giving you the feel of something unrealistic.
Additionally, sky with clouds, trees, and structure reflected on the water would help?
Ah, also make the displacement map larger. The ripples look a bit condensed. Although it isn’t impossible
Two different look for the water.
Thank you for your reply, I’ll try to make displacement map larger and I’ll try by adding some clouds trees etc.
And your rendering is great 
Thank you. They were actually made when I was a student. Looking back at it, I realized that I haven’t got tree reflections and I could have made it look a bit better. Oh well…Glad you like it.
A brick wall used as a floor may not look too realistic. Maybe you should use a different texture.
Also, reflective surfaces, to look realistic, need to have something to reflect, so you might have to add some more environment.
Just thoughts
Anssi
I would suggest that the part that looks “not real” is the brick texture. At the corners (where vertical surface meets horizontal) the brick runs different direction. Plus the map is too small, causing repetition of the same set of bricks over and over again. If you changes the brick texture, and added sky and background, I would say you are looking good!
Another issue is that the boundaries and corners of brick areas are unnaturally crisp. They look like razor-sharp straight lines.
