Junos upgrades across multiple versions are only tested from the EEOL versions, which are the last minor release of the particular year. For version 9 this will be 9.4. Starting in version 12 there are only 3 instead of 4 minor releases a year.
And the upgrade testing is generally only done up 2 major versions, from 9 to 11 in your case.
the safest route would be to get older versions from support and go in this order. You will need to open a case with JTAC to get older non-public files.
9.3 to 9.4
9.4 to 11.4
11.4 to 13.3
Steve Puluka BSEET - Juniper Ambassador IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP) http://puluka.com/home