Depends on your application, check list may vary, prepare check list based on your lower region deployment task and experience.
Some General list What my app follow on deployment and post deployment
1.Validate rulesets deployed are available in production
2.Validate rules count
3. Validate data instance values
4. Validate DSS, anything need to be updated with prod value
5. If you are integrating with external system
Make sure DB connection is good
Mask sure test SOAP and REST connection are good
if you have any other integration test those
6. If Agents are deployed - make sure agents are running in specified node - production region is always have more than one node
7. If listeners are deployed - make sure listeners connection are good and running on specified node
8. If UI changes are deployed - make sure UI renders without any issue
9. If new roles and access groups are deployed make sure it is available in application - if the application is connected with identity management system make sure new roles available in identity portal
10. If you deployed any Pega product hot fix - make sure it is deployed in prod.
Add all the task in excel and schedule a meeting with corresponding teams for application validation