.DRR File

File extension drr seems to be mainly related to Altium Designer PCB and FPGA software and used for one of its default file types.

A .drr file contains drill report, perhaps exported at the end of the session.

How to open:

It is likely that the .drr report can be viewed in Altium Designer. But perhaps it is a text file that can be viewed using any text editor.

How to convert:

Reports usually cannot be converted to anything else, and there is no reason to do so. However, sometimes they might be printed as PDF documents.