In Lightroom, the quickest approach is to filter the grid so you only see images with the orientation you want to correct, then rotate that filtered set in one step.

Try this:

1. Open the collection in Grid view.
2. Use the Library filter bar to filter by aspect ratio/orientation, such as Portrait or Landscape.
3. Review the filtered results to make sure they’re the wrongly rotated files.
4. Select all visible photos (Ctrl/Cmd+A).
5. Apply the needed rotate command.

If aspect ratio filtering alone isn’t specific enough, create a Smart Collection or metadata filter using image dimensions. For example, select files where height is greater than width (or use pixel thresholds that match your camera’s portrait files). That can isolate only one orientation from a specific camera resolution.

Be careful if any images have been cropped, since cropped files can also match those width/height rules. A quick visual check before rotating a large batch is a good idea.