Not sure what you're after. If you really want the min and max row and column only , then you can do what the others showed you, using find(), min(), and max().
If you want the min and max row and column because you want the bounding box because you want to crop out a rectangular region of interest from your image then you can use
props = regionprops(labeledImage, 'BoundingBox');
to get the bounding boxes of all the non-zero regions in your entire image. You can use the bounding box directly in imcrop() to crop out a region of interest. See my Image Segmentation Tutorial in my File Exchange for a full demo.
