To be considered an heir, you must be officially designated as his daughter. Since he can no longer acknowledge you, you may establish possession of status either by a notarised affidavit (Article 310-1 of the French Civil Code) or by a court judgment (Article 330 of the French Civil Code). This involves proving that he consistently acted as your father by caring for you and taking part in your upbringing. Any form of evidence is admissible to demonstrate this (Article 311-1 of the French Civil Code).
Please note that the notarised affidavit must be requested no later than five years from the date of death (Article 317 of the French Civil Code), and the court judgment within ten years (Article 330 of the French Civil Code).