I created a table with geometry type "GEOMETRY" AND inserted data of point, line and polygon type. My question is how to show this spatial data Qgis not supporting for geometry type "GEOMETRY".
Create distinct tables for each spatial feature, e.g. a table for point(s), a table for line(s), and a table for polygon(s). Then you can load these spatial tables as PostGIS layers.
There is also a ticket regarding this issue: http://trac.osgeo.org/qgis/ticket/167
It seems like it could be fixed only in QGIS 2.0.