Hello Rishika,
configurable products with PME are still supported. The good news is that you do not need the external tool to create product configuration models, the application is now part of WebUI.
However, to create actual configuration within an order item, you still need the J2EE stack to generate the UI. The J2EE UI is then embedded into WebUI screens.
To check all prerequisities, you should read through upgrade guides at SAP Service Marketplace. You can start, for example, here: https://websmp205.sap-ag.de/~sapidb/011000358700000745942013E/CRM713_UpgradePage.htm .
Regards,
Dawood.