Code:
oerr RMAN 20207
20207, 1, "UNTIL TIME or RECOVERY WINDOW is before RESETLOGS time"
// *Cause: UNTIL TIME and RECOVERY WINDOW cannot be less than the database
//         creation time or RESETLOGS time.
// *Action: Check the UNTIL TIME or RECOVERY WINDOW. If the database
//          needs to be restored to an old incarnation, use the
//          RESET DATABASE TO INCARNATION command.