Posting this from Zoho Support chat session today in case it's useful to anybody.

My question:  In Deluge, what is the system variable which returns the "Org" number for our CRM instance. For example, our URLs all start " https://crm.zoho.com/crm/org666xxxxx/" ; - how do I determine (in code) the "666xxxxx" bit for our instance?

Their answer:

You need to create a connection ( Go to Setup > Developer space > Connections) and associate the following code to use that connection

resp = invokeurl

[

url: " https://www.zohoapis.com/crm/v2/org"

type: GET

connection: "xxxxxx"

];

orglist = resp.get("org");

for each rec in orglist

{

orgid = rec.get("zgid");

}

info orgid;

Replace xxxxxx with the org name

Please refer the below link for more information to create a connection

https://www.zoho.com/crm/help/developer/connectors/set-up.html

(In follow-up chats they confirmed that there is no CRM Deluge variable which gives the same info. One must make a connection.)