RectOffset.RectOffset  

var rect = RectOffset (0, 10, 0, 10);

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    public RectOffset rect = new RectOffset(0, 10, 0, 10);
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    public rect as RectOffset = RectOffset(0, 10, 0, 10)