If you mean which unit is coupled to which unit, they are not kept in permanent pairs on the Jubilee Line so any list published of which unit is with which unit would only be useful on or about that date.
The 968xx* and 969xx cars are the de-icers, yes. They are in the even numbered units between 96080 and 96118 inclusive; that is twenty de-icing units in total.
*Not 668xx