A 38-year-old lawyer from Farmingdale, N. J., told the police yesterday that he had been kidnapped here Thursday afternoon by supporters of Fidel Castro, Cuban rebel leader. He said that he had been held in a Bronx apartment until Saturday morning.

He told the police that he escaped from four guards after grabbing a revolver and firing a shot into the ceiling.

Sidney Neubauer said his captors told him he had been kidnapped because a partner had not fulfilled an agreement on a $30,000 arms shipment with the rebels. Mr. Neubauerd said he was seized at Seventy-third Street and Amsterdam Avenue and taken to an apartment at 582 Westchester Avenue in the Bronx.

Magistrate Walter H. Gladwin held Joaquin Goméz, 24, of 395 Clinton Avenue, Brooklyn, in $1,000 bail and Louis Martinez, 34, a lawyer of Canton, Ohio, in $2,500 bail.

Goméz was reported to be secretary of the Directorio Revolucionario Club at 556 Amsterdam Avenue.