SQLCOD -204 has a message for that - SQL0204 - have you seen what that message is? It should be in your joblog - it says "File not found" - there should be some further info as to which file, but it is probably BIGFILE - there's nothing too complex about this - see where BIGFILE is on your system and be sure your LIBL is correct when running the SELECT statement.
Just for the future - if you need information on an SQLCOD, make a message ID by taking the letters SQL and follow them with a 4-digit form of the SQLCOD. If SQLCOD is in the 30,000 range, use SQ plus the number as the message ID. Look up in QSQLMSG - DSPMSGD SQLxxxx QSQLMSG.
I suspect there is nothing related to RRN in this error, other than the file you specify is not found, but that is also true about the FROM clause.