Please see the unedited screen captures below. While working on a reply to ritik_saxena I tried several methods for getting .CR3 raw files from a Canon RP to the Photos App on my iPad Pro via WiFi, and from there into Photoshop for iPad, aka Photoshop for Mobile: Canon Camera Connect and Cascable software, both using the camera's built-in WiFi; and CamRanger 2 hardware and software via CamRanger WiFi. I don't necessarily understand this, but here's what happened.
• All three methods brought the .CR3 raw files to Apple's Photos App. This was expected.
• .CR3 files imported to Photos App via Cascable did not open in Photoshop for iPad. "Unrecognized format."
• .CR3 Files imported to Photos App via Canon Camera Connect opened in Photoshop for iPad. In the editing window and in the Home Screen Cloud documents list they were shown with no file extension.
• .CR3 files imported to Photos App via CamRanger 2 hardware/software opened in Photoshop for iPad. In the editing window and in the Home Screen Cloud documents list they were shown with the file extension .CR3, even though they had, in fact, been converted to PSDC format as they were opened in Photoshop for iPad.
• Conclusion: No, you can't open raw files in Photoshop for iPad. But, depending on how you move them from your camera to your iPad Photos App you can import them and edit them in Photoshop for iPad as PSDC files.
Note that files imported to iPad via CamRanger keep their .CR3 extension.