I have a VCS server which I want to setup in DMZ for URI dialing outside/Inside, the domain name is same as our MEX record domain name, what SRV records I have to create in local or ISP DNS and publish in ISP DNS so whenever other corporate wants to do a video conference toour internal users or TP endpoint they can reach.
Zones, subzones and service policy are not determined by where you place the VCS. As suggested earlier, VCS-e is placed in the DMZ. To know how to configure the zones refer to the document I attached. There are examples there.
If the other company has a VCS-E that is accessible from the internet, then all you need to do is create a DNS zone and a search rule that that says any call not for my domain, send to the DNS zone. Again example is in the document I sent to you.
If you want a direct connection to the company then you will need to create a neighbor zone and search rule that will send all calls intended for this company to this zone.