I have a garmin gps72 but now i have move to other country first i was in india and now i am in saudi arabia when i put the coordinates its showing in many kilometers

You need to find what Map Datum your map is using, it should be printed in the margin or the title of the map. Then you need to set the Map Datum the same value in the GPS 72 (Main menu, Location Tab). Most modern maps and charts use WGS84 but I wouldn't know for Saudi Arabia.