Simple solution, stop trying to change directory.
Now why don't you give people more information to give you an intelligent answer:
- Is this on your RHEL6 server?
- Are you using RHEL6 as a client to another server?
- Do you have permissions to access the directory you are attempting to change to?
- If it's your own server then which FTP daemon are you using?
Try giving as much information about the problem and what you've tried to do so far to fix the issue.
Oh and this is a volunteer forum, people give their time for free to help others, so posting a question with zero information and wanting an answer "as soon as possible" is just plain rude. If you want "as soon as possible" then pay RedHat and make use of your support subscription and SLA.