Network.isClient

public static bool isClient ;

Description

Returns true if your peer type is client.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    void OnGUI() {
        if (Network.isServer)
            GUILayout.Label("Running as a server");
        else
            if (Network.isClient)
                GUILayout.Label("Running as a client");
            
    }
}