public class MainObject //Note: Does not extend MonoBehaviour, the Update method is called manually from a MonoBehaviour Update.
{
    public class InnerBase {}
        public class InnerMain : InnerBase
        {
            public void ChangePrimary()
            {
                cInput.ChangeKey("Input", 1);
            }
    }
    public class InnerTwo : InnerBase
    {
        public void SomethingUnrelated(){} //Including this to mimic the structure.
    }

    public InnerBase[] objects; //Note: Not putting the declaration in, but this is declared in a constructor in the actual code.
    public int index;

    public void Update()
    {
        if(!cInput.scanning)
        {
            if(cInput.GetKeyDown("Select"))
            {
            try
            {
                ((InnerTwo)objects[index]).SomethingUnrelated();
            }
            catch(IndexOutOfRangeException) { }
            catch(InvalidCastException)
            {
                try
                {
                    ((InnerMain)objects[index]).ChangePrimary();
                }
                catch(InvalidCastException) { }
            }
            }
        }
    }
}