How to make water reflection like in kingdom new lands

Hi how can ı make water reflection like in kingdom new lands

You render flipped objects, and add some additional effects.
Search for some tutorials on the internet.

ı thought ı can select all of the object on the scene and flip respect to x axix and add some blurr effect is there any easy way unity should definetly add some easy way

No. you should do it programmatically so it respects dynamic changes.