Please provide more information on the requirement (OS on source and target, DB version, application version, size of the database, downtime window, etc.)
In general, you should follow this document:
R11i / R12: Oracle E-Business Suite Upgrades and Platform Migration (Doc ID 1377213.1)
The following master document has references to many database related documents. Among them are the export/import and transportable tablespaces methods to relocate a database.
R11i - R12 Database Documentation Resources for E-Business Suite (Doc ID 1072409.1)