Hi brahma ,
I am new too websphere too.
based on my knowledge , you can rollback to the previous version by providing the offering id of the previous version.
./imcl rollback $WAS_OFFERING_ID -repositories "repositories path" -installationDirectory "installationDirectory"
or
./imcl install $OFFERING_ID -installationDirectory $WAS_BASE_HOME -repositories $WAS_ND_REPOSITORY -acceptLicense
or
./imcl uninstall interim_fix_name -installationDirectory product_installation_location