I am trying to connect the c wire but I'm at a crossroads of sorts. I have a dual zone so there are 2 thermostat wires come into what looks like a relay box ( see pictures) I have located the thermostat wires but I do t know where to connect the extra wire as there is nothing that indicates where the connection is
Ecobee has a Power Extender Kit and a lot of documentation on what to do when you don't have a C wire. See: https://support.ecobee.com/hc/en-us/articles/360009155051-Installing-your-ecobee-thermostat-with-the-Power-Extender-Kit-no-C-wire-
In your installation documents from Ecobee find the diagram for Taco sr503-4, that is functionally equivalent to your Argo control board. The "t" wires to the left of the diagram connect to the T terminals on the Argo board. You will need parts equivalent to a remote power supply for the Ecobee (see amazon "c wire power supply"), and an isolation relay (like a White Rodgers 90-380).