[...] I do not understand because I will give up and will not be concerned by this succession.
Indeed, in accordance with article 845 of the Civil Code, the heir who renounces is entitled to retain the donation he has received. However, it must not affect the legal reserve of other children (which depends on their number). That is why the notaire must reinstate the value of your gift to the estate assets , to verify that it does not encroach on the reserve of your brothers and sisters.
In addition, if your father has expressly required the gift report in the event of a waiver, Then the notaire must report its value in the assets of succession. If it exceeds the rights you should have had in the partition if you had participated in it, you will have to compensate the heirs accepting up to this amount.