Below ITMS 7.6 System Requirements
If any Os are missing mention system Requirements that OS does not support.
http://www.symantec.com/it-management-suite/system-requirements/
System Requirements
Management Server
- NET Framework 4.5.1 or above
- Internet Explorer 8, 9, 10 or 11
- SQL Server 2008 SP2 or above, SQL Server 2012 or SQL Server 2014
- Windows Server 2008 R2 or Windows Server 2012 R2
Site Server
- Windows Vista SP2 or later, 7, 8, 8.1 x64/x86
- Windows Server 2008, 2008 R2, 2012, 2012 R2
- Windows IIS
- Microsoft .NET 4.5.1 or above
Note: Win XP and server 2003 are no longer supported due to .net version
Workflow Server
- Windows Server 2008 R2 SP1 or Windows Server 2012 R2
- SQL Server 2008 SP2 or above, SQL Server 2012 or SQL Server 2014
- Windows IIS
- Microsoft .NET 4.5.1 or above
Windows Agent
- Windows XP SP3 or later x64/x86
- Windows Vista SP2 or later x64/x86
- Windows 7 x64/x86
- Windows 8/8.1 x64/x86
- Windows Server 2003 SP2 or later
- Windows Server 2008 SP2 or later x64/x86
- Windows Server 2012 or later
UNIX Agent
- IBM AIX 6.1, 7.1
- HP-UX 11i v3 (PA-RISC /IA-64)
- Sun Solaris 10 (SPARC/x86/x64), 11
Linux Agent
- Red Hat Enterprise Linux WS\ES\AS 5.10 x64/x86, 6 x64/x86, 7
- SUSE Linux Enterprise Desktop 10 x64/x86, 11 x64/x86
- SUSE Linux Enterprise Server 10 x64/x86, 11 x64/x86
- VMware ESX Server 4.0 (Agentless), 5.0 (Agentless)
Mac Agent
- OS X 10.8, 10.9, 10.10
- OS X Server 10.8, 10.9, 10.10