I want to transform it to another PCS "WGS_1984_UTM_Zone_48S".
What can I do?
You can use the Project Tool if it's vector data or the Project Raster Tool. There's a geographic/datum transformation that converts between DGN 1995 and WGS 1984. You can also project the data on-the-fly in a map or scene.
Are these not working for you? If not, are you getting any warnings or error messages?
Melita