HVR supports capturing changes from Oracle even if the datafiles are automatically managed by ASM or not. If your Oracle uses ASM to manage the redo logs, you will then need to provide access information for the ASM user. HVR then uses the ASM API to capture the chanages. If ASM is not used, then HVR will perform a direct read against the redo log files at the filesystem. It has been observed that that speed of capturing changes from direct disk reads performs faster than when the database uses ASM.
I hope that helps. So yes, HVR support capturing from Oracle with or without ASM. We also support capturing from the primary database or from a standby instance.
Good luck with your replication projects.