How to create a new Lower environments like Dev, Test or UAT from Appian PROD environment?

You cannot. This isn't something in our control. There is a lot associated with it. Talk to Appian. Raise a support case or talk to your contact person in Appian. 

You can’t recreate environments with production data per se but you could import the application package back in to the lower environments and recreate an empty schema (with the exception of reference data tables).