Hi Premkumar,
There is one parameter file for each MaxDB instance - the currently active one.
It's the file /sapdb/data/config/<SID>.
As your current file seems to be have some problem , you may rename it and run a
param_restore 1 ( 1 - Last updated version )
to get the last backed up version of it back.
Note :If you modified the volume configuration before the file got problem and no backup version of the parameter file had been created since than, restoring the old version will make your database unstartable.
The missing volume configuration parameters would then need to bee added manually again.
Hope this helps.
Regards,
Deepak Kori