Remove NSX from Vcenter Server:
We will remove below components from vcenter :
VXLAN
Logical Switches
Logical Routers
NSX firewall
NSX Plug-in
VTEP Interfaces
Steps: -1 Delete the Transport Zone and remove connected VMs
2- Unconfigure VXLAN from “Host Preparation” tab

3- Un-install VIB from the “ Host Preparation” tab

4- Go to – Managed Object –
Click- Content

Click -Extension Manager

Click Unregister Extension:

Enter String Value : com.vmware.vShieldManager and Click on Invoke Method

Output should be void:

Again Enter String Value : com.vmware.nsx.ui.h5 and Click on Invoke Method

5- Remove NSX directories from vcenter appliance :
Path for vcenter UI- /etc/vmware/vsphere-ui/vc-packages/vsphere-client-serenity
Path for vcenter web client- /etc/vmware/vsphere-client/vc-packages/vsphere-client-serenity/
com.vmware.nsx.ui.h5.*
com.vmware.vShieldManager.*
-Restart UI or webclient
In my case directory seems to be already removed :

6- Verify if any residue vtep dvsport groups and if any delete manually.
7- Now NSX has been removed successfully from vcenter. Re-login vcenter and check .