I'm not sure about your requirement.
I have to transfer internal table data to excel file(.xls),then i have to upload this .xls file to FTP server
What stops you from downloading the table as excel on presentation server and then upload the xls to your target server? (TA CG3Z)
If this is not an option, maybe you should take a closer look on
abap2xlsx - ABAP Development - SCN Wiki
Best regards - Jörg