public void Cycle()
{
    //Increment index
    Index++;

    if (Index == list.Count)
    {
    Index = 0;
    }

    //Perform the cycling.

    //For each in the list of objects...
    for(int i = 0; i < list.Count; i++)
    {
        //Check if they're active
        if (list[i].active)
        {
            //If it isn't the object you seek disable it.
            if (i != Index)
            {
                list[i].SetActive(false);
            }
        }
        else //If it's inactive...
        {
            //If it's the object you seek, enable it.
            if (i == Index)
            {
                list[i].SetActive(true);
            }
        }
    }

}