MovieTexture.Pause  

// Assigns a movie texture to the current transform and pauses it immediately

var movTexture : MovieTexture;

function Start () {
    renderer.material.mainTexture = movTexture;
    movTexture.Pause();
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    public MovieTexture movTexture;
    void Start() {
        renderer.material.mainTexture = movTexture;
        movTexture.Pause();
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    public movTexture as MovieTexture

    def Start():
        renderer.material.mainTexture = movTexture
        movTexture.Pause()