Chac: Dios de la lluvia, also released as Chac: the Rain God and simply Chac, is a 1975 film written and directed by Rolando Klein. The film involves modern Maya peoples invoking the traditional rain deity Chaac. The film is in the Maya languages. The majority of the cast speak Tzotzil Maya, but one of the main actors, Pablo Canche Balam who plays the shaman, speaks Yukatek Maya.
I saw this movie years ago. As I remember it, the villagers are desperate for rain, and call upon a Mayan shaman who performs many rituals. But the rain does not come. The villagers become upset. The shaman says rain will come. But it does not. Eventually, the villagers turn on the shaman and kill him. And as his blood soaks into the earth, the rain comes.
I saw the one with Burt Lancaster, and there was some guy beating a drum.