The provided source material does not contain information regarding a city named Ratu in India. Instead, it identifies "Ratu" as an Austronesian title used by male Fijians of chiefly rank, with "adi" serving as the equivalent title for females of chiefly rank.
In the Malay language, ratu is also a traditional honorific title referring to a ruling king or queen in Javanese culture. This linguistic connection is reflected in the term "keraton," which refers to a royal palace in Java and is constructed from the circumfix ke- -an and the word Ratu.