The indictment was made on the recommendation of Department of Special Investigation (DSI) investigators handling a special case against 51 PDRC members and supporters.
The 51 include six academics and university lecturers who gave speeches on PDRC rally stages.
But prosecutors decided not to indict one of the six because the content of his speech involved stock information and corruption and did not incite public disorder, OAG spokesman Nantasak Poonsuk said.
Among the group is Thawil Pliensri who appeared on the PDRC protest stage several times before being retroactively reinstated as secretary-general of the National Security Council (NSC) in March.
Mr Nantasak said none of the accused had yet to report to investigators to acknowledge the charges and give statements. The DSI investigators must summon them for inquiries and submit an additional report to prosecutors.
“The investigators were not given a deadline on when to finish this process but they should proceed quickly, although the case has a 20-year statute of limitations,” Mr Nantasak said.
Prosecutors had prepared 500 witnesses comprising officers from the police, intelligence and security agencies to testify in court, but the number of witnesses to be called would depend on the court’s discretion, he added.