ROWID is a reserved word and cannot be referenced in the WHERE clause in R5. It is allowed in JOIN INDEX creation.
In R5.0.x you can enable the "use" of ROWID, for backward compatibility purposes, with a INTERNAL flag setting in DBSCONTROL; but technical issues are not supportable as it is explicitly stated that ROWID is not supported in SQL query syntax in R5.
After R5.0.x, NCR has disabled the DBSCONTROL setup option. So in the Teradata RDBMS newer than R5.0.x, ROWID is not allowed to be queried by using SQL.