Hi Atanu and Antara,
This output indicates that your connection has succeeded and you were able to authenticate, but the switch to passive mode has failed. This most often occurs due to firewalls which inspect packets sent to the FTP control port (21) in order to read the PASV command to configure access through the firewall dynamically. I've posted some information about this process on our Biostars site here:
If switching to implicit FTPS does not solve the problem for you, please check with the network or security administrators at your site to see if outbound ports in the range 30000-31000 are blocked, and whether they can be allowed, at least to the Galaxy FTP servers.
--nate