As of June 9, 2016 with the release of NSX for vSphere 6.1.7, the EOGS date has been extended by 3 months, to January 15th, 2017. This is to allow customers to have time to upgrade from NSX for vSphere 6.1.7, which contains an important security patch improving input validation of the system, to the latest 6.2.x release. For recommended upgrade paths, refer to the latest NSX for vSphere 6.2
For those than can upgrade to NSX-v 6.2.3 there is a current issue around the upgrading of NSX and existing edges possibly becoming unmanageable. This issue occurs when the load balancer is configured for serverSsl or clientSsl but ciphers value is set as NULL in the previous version. NSX-v 6.2.3 introduces a new approved cipher list in NSX Manager and does not allow the ciphers to be NULL when configuring the load balancer…as was the previous default option.NULL in the earlier version, if this is not set NSX Manager 6.2.3 considers this ciphers value as invalid the Edges in turn become unmanageable. There should be a fix coming and there is a workaround as described in the VMwareKB here.