I am trying to create a set of 2ft contour lines in ArcGIS Pro and I have a set of 6 or so .tiff files. I have mosaiced them together into 1 .tiff file. I tried running the contour analysis tool on the file and ended up with an impossibly large contour dataset that doesn't look right at all. Do I need to use a different file format? I've used a DEM in the past and that worked just fine, but there don't seem to be DEMs available in the area I'm working in. I don't know how to work with .tiff files, so I'm not sure just what else to do with it.
tiff is a file format. It does not dictate the content of the file. Are you tiffs elevation data? or are they something else?
You can contour anything, since the contouring process has no clue what the numbers actually represent. Perhaps if the results don't make sense, then the tiffs don't contain elevation data
Please post a picture of the output so that we can see what you mean by incorrect.
And to note, think of contouring as slicing a potato into horizontal slices. In your case each slice is 2ft in thickness.