No you cannot fry foods using water because the water is not the same as oil.
Water boils and so you'd actually be boiling the foods you put into water instead of frying the foods.
The oil gets to a hotter temperature than the water does and it doesn't boil off so the oil fries the foods and cooks them by frying them.
If you use water in a deep fryer then all that will happen is the food gets boiled and not fried.
So if you want to fry foods you need to use cooking oil and if you want to boil foods then you would use the water.