More than half the remaining 72 American survivors of the Jonestown Peoples Temple mass murder-suicide were cleared today to return to the United States this weekend, Guyana's assistant police commissioner said.

Cecil A. Roberts said he was still working on the list of those not wanted as suspects or material witnesses in the Nov. 18 deaths of more than 900 Americans. The FBI announced in New York that six survivors would arrive at Kennedy airport Saturday and 37 more Sunday on commercial flights.

Meanwhile, a four-man FBI team joined an investigation here into the murder of Rep. Leo J. Ryan (D-Calif.) that preceded the mass deaths. The U.S. Embassy said the team comprised technical experts who will examine evidence collected so far. The Guyana government said that one of the FBI experts will assist local policr. The embassy also reported the arrival of a State Department lawyer.

Eight elderly survivors of the mass deaths already have been allowed to return to the United States because of their age.

Stepney Kibble, a U.S. Embassy spokesman, said he had not been officially informed and was not sure if the survivors would return by commerical airliner or military plane.

The spokesman said many would have to be released before a military flight could be requested. Kibble said the penniless survivors had to sign promissory notes for the cost of their transportation.

Two of the survivors have been charged with murder. Charles F. Beikman is to appear at a preliminary hearing Monday on charges of murdering a cultist and her three children at the Georgetown cult headquarters.

Charged with the earlier murder in the killings of Ryan, three newsmen and a disaffected cultist is Larry Layton of San Francisco. The congressman was investigating reports that the cult leader, the Rev. Jim Jones, was holding some cultists against their will at the commune, about 150 miles northwest of here.

The embassy's second-in-command, Richard A. Dwyer, 45, is back at his desk, his body still carrying the bullet fired at him by the cultists who killed Ryan.

"It hurts more now than it did when I was shot," he said, sitting down gingerly. Doctors decided to leave the bullet lodged near his pelvis. He had escorted the Ryan party to the Jonestown camp when the group was attacked Nov. 18.