About all you can do is look at the Application Event logs, look for Dell or DUP. you can also look for a folder (assuming Windows) called Dell\updates to see if the log files for the last updates are there.
you can also download the SUU 6.5.1 which was the last one to support the 6850, and it will compare what you have to what the last updates were. www.dell.com/.../poweredge-6850
NOTE: you have to dnload all 3 iso segments and concatenate them into one iso using this command in Windows, see the "Additional Information" section for a bit more detail
Windows: copy /b om* om651_suu_a00.iso