Hi Badar - I think for this type of migration you might want to contact Esri Support for assistance. If that's not a possibility, though, just know that the Esri help doc is super helpful in this case. Our ArcGIS 10.3.1 documentation states:
"You can upgrade directly from a 9.3.1, 10, 10.1, 10.2, 10.2.1, or 10.2.2 geodatabase to a 10.3.x geodatabase if your database is at a supported release."
Upgrade a geodatabase in Oracle—Help | ArcGIS for Desktop
The "supported release" means that your Oracle version has to be supported for the ArcGIS version you are upgrading to. ArcGIS 10.3.1 geodatabases are supported at Oracle 10.2.0.3:
Oracle database requirements for ArcGIS 10.3.x—Help | ArcGIS for Desktop
So it is fully supported for you to upgrade directly from 10.0 to 10.3.1, then migrate your database to Oracle 12c using a datapump export/import.