NEW DELHI, Dec 19— The Rajya Sabha today unanimously passed the Scheduled Castes and Scheduled Tribes Orders (Second amendment) Bill, 2002 without any discussion, paving the way for modification of the ST and SC lists in 20 states involving 140 communities. The Bill was passed by the Lok Sabha here yesterday after a thorough discussion that saw tribal members from Assam opposing the entry of Koch-Rajbongshi community in the ST list. The case of the Kochi-Rajbongshi community has been strengthened by recommendations of the National Commission for SC and ST and the Parliamentary Standing Committee on Labour.