how to find untagged objects

i want to add a script to every untagged object in the game is this possible

Yes it’s possible. It seems like you can’t find the “Untagged” directly with FindGameObjectsWithTag but you can compare it as a string.

#pragma strict

function Start () {
    AddScriptToUntagged();
}

function AddScriptToUntagged () {
    var allGameObjects : GameObject[] = GameObject.FindObjectsOfType(GameObject);
    for (var go : GameObject in allGameObjects) {
        if (go.tag=="Untagged") {
            go.AddComponent(TheScript); //Enter the name of your script here
        }
    }
}