Date: Maybe the 50s.
Country of origin: The U.S. or a European "western", the questioner saw it with Hungarian dubbing.
The movie's two main characters are a father and his son. For some reason they get separated and the boy grows up to be some sort of law enforcement official and the father is a famous bandit. The boy is trying to hunt down his father without knowing the relationship between them.
At some point it, because of a necklace or a family pendant they (or just one of them?) realize the connection.
The questioner believes that the title was something like The Sons of Rio bandits or The Sons of the Rio gang.
I think it's not Gunmen of Rio Grande (1964) or Bandits of the Rio Grande (1965).