Tenants at 50 Follen St. will file a complaint with the Cambridge Rent Control Board on Friday, charging that apartments in the building have been taken off the market illegally and converted into condominiums.

About 16 of the remaining 45 rental tenants decided Sunday to bring their complaints to the board, which is considering a $100 rent increase requested by the owner. Saul Moffie of Beacon Hill, Gilbert Mason, a tenant, said yesterday.

Cambridge ordinances require that owners of rental units receive permits from the Rent Control Board before taking the apartments off the rental housing market for conversion into condominiums.

The ordinances specify that only renters who lived in the housing complex before Aug. 10, 1979, may occupy the new condominiums without a permit.

No permits have been granted for condominium conversion at 50 Follen St., Peter Stanton, director of the board, said yesterday, adding that "a couple were denied because of the housing shortage."

Moffie was unavailable for comment yesterday but Douglas A. Yoffe, the manager of the housing complex, which is located next to the Cambridge Common, said that some violations of rent control ordinances governing conversion to condominiums probably do exist.

"I've sold them to people who were aware of the laws," Moffie said, adding. "It's not up to me to enforce the law."

At least 30 of the converted apartments are occupied by people who have moved in since the 1979 cutoff date. David H. Gibbs, a tenant, said yesterday, adding that the condominiums have sold for up to $80,000.

Basically, the owners have said to hell with the law," Gibbs said.

City Councilor David L. Sullivan, who met with the tenants on Sunday, said yesterday that there appear to be about 30 violations at the Follen St. complex.

"It seems to be a massive violation of the removal ordinance." Sullivan said, adding that the Rent Control Board should take the occupants and the developer to court.