QUICK NOTE:
Microsoft just updated its support matrix for Lync 2013 (Finally) Where Netscaler is listed as supported for Reverse Proxy and for Load balancing –> http://technet.microsoft.com/en-us/office/dn788945
You can also read the deployment guide for Netscaler and Lync here –> http://www.citrix.com/content/dam/citrix/en_us/documents/partner-documents/microsoft-lync-2013-citrix-netscaler-deployment-guide.pdf