I have generated the .drl and .art files for my PCB for manufacture in Allegro 16.2.
But, I want to import them and verify that it actually properly generated.
Please tell me how I can import and verify that it is correctly generated.
There are a lot of Gerber file viewers available, both free and otherwise. You can also import the artwork (gerbers) into an Allegro board file using File => Import => Artwork. You can specify unused layers in your current design, or create a new board file in your directory specifically for viewing the artwork.