Get Android Mac Address

Hello, I have been trying this for some time, still with no luck, I have found this code on internet, and works on my OSX but not on an Android Device. Any clue?

 #pragma strict
 
  import System.Net;
  import System.Net.NetworkInformation;
 
  
  var myMacAddres = "";
  
  function Start () 
  {
      GetMacAddress();
    //  if(GetMacAddress() != MacLicence)
      //    Application.Quit();
  }
  
  function Update () {
  
  }
  
  function GetMacAddress()
  {
      var macAdress = "";
      var nics : NetworkInterface[] = NetworkInterface.GetAllNetworkInterfaces();
      var i = 0;
      for (var adapter: NetworkInterface in nics)
      {
          var address: PhysicalAddress = adapter.GetPhysicalAddress();
          if(address.ToString() != "")
          {
              macAdress = address.ToString();
              myMacAddres = macAdress;
     
              return macAdress;
          }
      }
      return "error lectura mac address";
      
      
  }