@Thangarajan Pannerselvam
If your GetFTP processor is configured with "delete original" set to false, every time this processor runs it will pull all th the files it finds including those pulled in the last run of the getFP processor.
The ListFTP processor maintains state unlike the GetFTP processor. so if you replace your GetFTP with both ListFTP and FetchFTP processors, you will not see the same files pulled twice unless the timestamp on the files on the FTP server are updated.
Thanks,
Matt