I have planetosm data file which is nearly 18GB now i need to seperate and get only my country details. Is there any way to seperate that data from osm file? I'm using OSGEO 6.05
Consider using the WeoGeo Market where you can download only specific layers of the planetosm and limit the geographic area you obtain. http://market.weogeo.com - free access and OSM is free too there. Just create an account.
Did you take a look at the daily snapshots from http://download.geofabrik.de ?