Hi Kavitha,
To narrow download, could you offer us the following information?
1. Where the document library locates at? (Team site library or SkyDrive Pro library)
2. May I know if you can access the folder from Office 365 portal in the web browser?
In addition, I would like to know if you have installed the Microsoft Office for Mac 2011 Service Pack 3?
If not, you can try installing it via the link below:
http://www.microsoft.com/en-us/download/details.aspx?id=36503
Thanks,
Wilfred