An heir who has been appointed to the succession both under the will and under the law can reject the succession. In order to decide whether or not to accept the inheritance, we have up to six months from its opening, i.e. from the date of the testator's death.
If the testator has appointed several testamentary heirs and one of them does not want or is unable to be an heir, the share allocated to him, in the absence of the testator's will to the contrary, falls to the other testamentary heirs in proportion to the shares allocated to them.