If an immovable has been given, and the donee hath it in his possession at the time of the partition, he has the choice to make the collation in kind or by taking less, unless the donor has imposed on him the condition of making the collation in kind, in which case it can not be made in any other manner than that prescribed by the donor, unless it be with the consent of the other heirs who must be all of age, present or represented in this State.