A bitmap image has pixels, and thus the pixel count is usually the best indicator of quality.
And yes, if you're printing in CMYK, TIFF is an excellent choice for format, as CMYK usually converts well for RGB output.
If you use Photoshop to open up the image in question, what is the pixel count? That number divided by 300 gives you a reasonable approximation of the max size at which you can use that image, assuming that the image is acceptable at 100% in Photoshop.
The Object Properties panel in FrameMaker is a bit odd; my understanding is that you can specify either scale or resolution, but it's not a calculator.
Thus, if you set DPI for 300, you basically get the max size at which you can safely print at a 150 linescreen or lower printer.
In the example shown below, setting the DPI to 300 shows the image has only 25% of the pixels needed to print at a commercial printer. And, true to form, opening that image in Photoshop shows it's only 600 pixels tall, and I'd only be able to print it at 2" tall if I'm following my printer's specs. For those that are curious, check the C:\Program Files\Adobe\Adobe FrameMaker 2022\Samples\UserGuide(Arabic,English,Hebrew) folder for the General-Description.fm file shown in my example
... View more