Photos with .DNG and .MRW extension

Here is the faq reference:

https://community.adobe.com/t5/photoshop-elements/faq-will-photoshop-elements-work-with-my-camera-or-why-won-t-my-raw-files-open/td-p/4303022

DNG is an open (non proprietary) raw file format which can be opened, edited and converted to image formats by any raw converter including Elements.

Other supported proprietary raw formats are mentioned in the links in the above faq:  each camera model comes with its own particular format.

So, no problem with DNG, for other formats, refer to the list of supported cameras, then check if the needed ACR converter version is available to your Elements versions. If it is not (yet), then you can use the free Adobe DNGconverter to transform it to DNG.