Tally Software has Licensing model where it supports single user to multi-user mode.If you want to implement Tally in your organization, you need to have single VLAN for Client- Server Model to work. If your organization has multiple VLAN like, server VLAN is different from Client VLAN, then Tally client does not discover the Tally server. this is familiar problem to the Tally company, but they are failed to provide any solution to fix this problem.
Tally Server client Model on different VLAN
If you have ESX server and Tally virtual server hosted on it. Create a separate Vswitch and add a dedicated physical network adapter,specify the VLAN ID for this port group which is same the client side VLAN ID
Add the Tally Virtual server network card to connect to this Vswitch. Assign the IP Address to Tally server with the same range of client PC.
Now connect the ESX host physical network adapter to the Physical switch to a port, then you have to configure the switch port to Access mode and allow the client VLAN to access this port.
Now the Client PC will be able to detect the Tally server and License will be assigned.
Tally server should be enable with Terminal services, Multiple users can do a remote desktop connection to the server. But this solution will be expensive with Terminal service License and Windows Licenses.