If the output of the PRINT is just a blank line, then one or more of the variables contains a NULL, as Mike stated above.

You probably would have to use a somewhat more "complicated" way to do the print:

PRINT 'BEFORE NEW SRNO STARTS @MobileCode= '+COALESCE(@MobileCode,'')+' @MobileCodeNew ='+COALESCE(@MobileCodeNew,'')+'@MobileCodeForN ='+COALESCE(@MobileCodeForN,'')+'@RCOOC ='+COALESCE(@RCOOC,'')+'@MobileCodeForN ='+COALESCE(@MobileCodeForN,'')

That way you can at least identify which one is the culprit. This will also give you an output as Adam posted above.