How to find in which release my Salesforce org is running?

1. Go to status.salesforce.com

2. Select your instance.

3. Check the Version.

(or)

1. https://[instance].salesforce.com/services/data/

https://[domain].lightning.force.com/services/data

Example:

https://cs92.salesforce.com/services/data/

https://cs92.lightning.force.com/services/data