It does not seem like the existing integration with Zoho CRM works from RingCentral Android app. It does not allow to create CRM contact from incoming call/message. Does not allow to read/create any info for contact in CRM.
Also, "Send Text Message" from Zoho CRM contact opens in the native phone app instead of Ring Central.
Only things I was able to get working was call logging for existing Zoho CRM contacts and calling an existing contact in Zoho CRM actually calls with Ring Central.