Well, as it says on the download page:
Oracle Database 10.2 and 11.1 are no longer available for download. The software is available as a media or FTP request for those customers who own a valid Oracle Database product license for any edition....
Oracle database server/client 10gR1, R2 and 11gR1 is NOT available for download on the OTN or edelivery.oracle.com.. You need to raise an NON-TECHNICAL SR with Oracle Support
Following documents will help you to raise NON-TECHNICAL/media request SR with Oracle
1. FAQ: Downloading 9i, 10g, and 11g database media/ftp request e software media (Doc ID 1476075.1)"
2. How to Request Physical Shipment or Download URL for Software Media (Doc ID 1071023.1)