Bishops:
Joseph Ratzinger, Pope
Agostino Vallini, Cardinal, Vicar General
Armando Brambilla, Auxiliary Bishop
Enzo Dieci, Auxiliary Bishop
Ernesto Mandara, Auxiliary Bishop
Luigi Moretti, Auxiliary Bishop
Paolo Schiavon, Auxiliary Bishop
Benedetto Tuzia, Auxiliary Bishop
Camillo Ruini, Cardinal, Vicar General Emeritus
Filippo Giannini, Auxiliary Bishop Emeritus
Suffragan Dioceses:
Albano (Suburbicarian See)
Anagni-Alatri
Civita Castellana
Civitavecchia-Tarquinia
Frascati (Suburbicarian See)
Frosinone-Veroli-Ferentino
Gaeta (Archdiocese)
Latina-Terracina-Sezze-Priverno
Montecassino (Territorial Abbey)
Palestrina (Suburbicarian See)
Porto-Santa Rufina (Suburbicarian See)
Rieti (-S. Salvatore Maggiore)
Sabina-Poggio Mirteto (Suburbicarian See)
Santa Maria di Grottaferrata (Territorial Abbey)
Sora-Aquino-Pontecorvo
Subiaco (Territorial Abbey)
Tivoli
Velletri-Segni (Suburbicarian See)
Viterbo
A suffragan diocese is a diocese in the Catholic Church that is overseen not only by its own bishop but also by a metropolitan bishop. The metropolitan bishop is always an archbishop who governs a diocese strictly his own, while he presides at the same time over the bishops of a well-defined ecclesiastical province composed of his suffragan dioceses. The bishop of a suffragan diocese is called a suffragan bishop.
Sources:
catholic-hierarchy.org/diocese/droma.html
en.wikipedia.org/wiki/Suffragan_Diocese