Roko is a title used by Fiji of chiefly rank specifically from the Lau Islands

Lau Islands

The Lau Islands of Fiji are situated in the southern Pacific Ocean, just east of the Koro Sea. Of this chain of about one hundred islands and islets, about thirty are inhabited...

. Its equivalent from the Kubuna Confederacy

Kubuna Confederacy

Kubuna is one of three confederacies which comprise Fiji's House of Chiefs, to which all of Fiji's chiefs belong.-Details of Kubuna:It consists of the provinces of Tailevu, Naitasiri, Lomaiviti, and parts of the western provinces of Ba, Ra...

 is the Bauan form of Ratu

Ratu

Ratu is a title used by Fijians of chiefly rank. An equivalent title, Adi is used by females of chiefly rank.-Etymology:Ra is a prefix in many titles and Tu is simply "chief"...

 and Ro

Ro

Ro is an a priori constructed language created by Rev. Edward Powell Foster beginning in 1904. In Ro, words are constructed using a category system. For example, all words starting with "bofo-" signify colors; the word for red is "bofoc", and yellow is "bofof"...

 from parts of the Burebasaga Confederacy

Burebasaga Confederacy

Burebasaga is the largest of the three confederacies that make up Fiji's House of Chiefs, to which all Fijian chiefs belong.-Composition of Burebasaga:...

. This title was widely used amongst members of the chiefly Vuanirewa

Vuanirewa

The Vuanirewa is the ruling tribe of the Lau Islands, a scattered group of more than a hundred islands and reefs along the eastern edge of Fiji.- Origins :...

 clan up to the mid 19th century. Increasing intercourse amongst the chiefly households of Lakeba

Lakeba

Lakeba is an island in Fiji's Southern Lau Archipelago; the provincial capital of Lau is located here. The island is the tenth largest in Fiji, with a land area of nearly 60 square kilometers. It is fertile and well watered, and encircled by a 29-kilometer road. Its closest neighbors are Aiwa...

 and Bau, thereafter, saw the increasing use of Ratu and Adi

Adi (title)

Adi is a title used by Fijian women of chiefly rank, namely female members of chiefly clans. It is the equivalent of the Ratu title used by male chiefs. It is in general use throughout most of Fiji, although on Kadavu Island, Bulou is used instead....

 by members of the Vuanirewa dynasty. The current heir to the Tui Nayau

Tui Nayau

Tui Nayau is the title held by the Paramount Chief of the Lau Islands in Fiji and is synonymous with the title holders over lordship of these islands. When translated Tui Nayau means Lord of Nayau, an island north of Lakeba, the latter accepted by many to be the chiefly island in the Lauan...

 title, Finau Mara

Finau Mara

Ratu Alifereti Finau Mara is a Fijian lawyer, politician, and diplomat. He is best known as the eldest son of former Prime Minister and President Ratu Sir Kamisese Mara. Since December 2001, he has held the official position of Roving Ambassador and High Commissioner, representing Fiji's interests...

, uses the Baun title Ratu instead of Roko. This is true for all of his siblings apart from his younger brother Tevita Uluilakeba