Hello Vinoth,
You are running the command (param_directget _UNICODE) in a wrong way. First connect to the database as control/dbm user and then run "param_directget _UNICODE"
From the attached output, it looks like the DBUPDATE never went through, as you can see you can still see the current registered version is 7.3.0.35.
What is the OS version you are using (32bit or 64bit ) ?
What version of MaxDB 7.5 upgrade DVD (32bit or 64bit) are you using ??