@SMNCP I believe the FTP site needs to be sFTP and there's an n/sftp module. You should find what you need in Help. Failing that there's a good video / article and toolset here: https://ursuscode.com/netsuite-tips/suitescript-2-0-sftp-tool/

Thank you Nelliott. Do you have any other sample scripts for the same? it would be much helpful. Thanks in advance.

sample scripts to retrieve a file via sFTP? Maybe, but the help section I feel sure has examples. It's actually really easy it's just a bit fiddly putting everything together including the password GUID required.