A photo would certainly help but "completely brown" is not a promising sign :-( Sounds like either a root rot from too much water or dessication from not enough.....can't be sure without seeing the plant and what its potted in. Either way, if completely brown, it is unlikely it will make a rebound.

Growing a rosemary (or just about any other kind of herb) indoors is not a easy thing to do - too dark, too dry, too warm. Even very experienced gardeners can have issues with this.

I did try to add a photo earlier. I think it is past the point of return unfortunately.

Oh, yeah!! That's a goner :-( But you can save a few stems to toss in your fireplace or wood burning stove. It will smell wonderful.

That one looks pretty bad.

You might salvage a few green(er) cuttings and root them to try again.

Getting the water right with Mediterranean herbs is difficult. Using the right growing mix helps with that. Check the "containers" forum on here for some "home made" mix recipes. If you want to use commercially available growing mixes, I've found that "cactus/citrus" mix or "bonsai mix" works reasonably well.

The more difficult issue with growing rosemary (and basil, sage and some other Mediterranean herbs) indoors in the winter is getting "full sun" lighting for enough hours per day. I use very bright "spot" lights over each of my plants. For Rosemary and Basil in 8" or 10" pots, I have them in lighted hanging planters with 800 lumen reflector spot lights about 6" above the tops of the leaves. My lights are on a timer for 14 hours per day. For the herbs, I either use aquarium lamps (blue and white mix) or "daylight" conventional spot lights from normal sources (Walmart, Home Depot, Lowe's, etc.) I'm not seeing much difference in growth and plant health between the "daylight" bulbs from local sources and the much more expensive "aquarium" bulbs from online. The "blooming purple" "grow lights" you see online (red and blue, with much more red than blue) are great for things you want to bloom, but are less optimal if you're trying to grow leaves. My herbs struggled with those lights last year, and I've moved those bulbs to other plants that I want to promote blooming and fruiting (tomatoes and peppers mainly).

Rosemary and sage wood are great additions to the smoker when smoking meats. They add a wonderful aroma and flavor to the smoke, and to whatever you're cooking/smoking.

Yeah, your plant looks like it's a little too far gone to be saved. Growing rosemary in containers have always been tricky. I grow mine in light, airy, soil;a cacti mix maybe?