There is a scenario where an organization is running both PureCloud and Skype for Business. There are mutually exclusive set of users using the respective platoforms.
What are the possbilities of integrating realtime presence of a Skype for Business user into PureCloud?
For example one such scenario could be that a PureCloud user searches for Skype for Business user, probably in PureCloud External Contacts, and can see his/her presence as exists in Skype for Business at the moment.
Is this integration possible as of now? or planned in future?
What other possibilities exist for such an integration as of today?
The only way to set a presence in PureCloud is to have an actual user created for each person and use the Presence APIs to set that user's presence. This would require each user to have an account, however, and would probably be confusing to PureCloud users because it would look like a real user account that they could chat with. For more information on the Presence APIs, see the article Understanding Presence.
You could use the External Contacts APIs to create contacts for your SFB users, but external contacts don't have presence. You'd have to repurpose some property on the user for their SFB status. If you're going to go that route, I'd suggest Title or Organization since they display on the external contacts overview in the UI. There is ongoing work to allow custom fields on external contacts, but it is not released yet.
Also, I've logged an enhancement request to have a way to sync presence information for non-purecloud users.