We are going to setup a standby DR database for the primary DB. The primary DB is in Oracle ASM. Can we setup the standby DB in regular flat file system, instead of using ASM?
I've never done it, but given that it is quite possible to have a given database with some data files on ASM and others on the file system, I don't see why not.
What keeps you from testing it and see for yourself? Use VirtualBox to create two separate vm's on your desktop and build the proof-of-concept there.