Module Relationship metadata API needed

Module Relationship metadata API needed

Hi Zoho Team,

Currently I am using "Free Edition" of Zoho CRM to consume the API's. 

While going through documentation for " updateRelatedRecords" API, I am facing an issue. 
I see that there is a  delink method to disassociate related records in Zoho CRM using Zoho CRM API but I don't see any method to find the list of all the modules that can be related to a particular module.
Is there any API to see the same? Basically I am looking for a metadata call to check this information.
Can you please provide me any means to find out which modules can be related to which all the other modules?

The documentation I am referring to:

Thanks in advance!

Warm Regards,
Neha