, welcome to NGA/ATP.
These plants (it looks like there were several in the one pot) has had a long-standing watering issue, compounded by what looks like sunburn. The potting soil needs to be well-draining, but fiddle leaf ficus do best when the soil is kept constantly moist (never soggy-wet though).
I feel sure that with the proper lighting, good potting soil, and water/fertilizer, you can bring those plants back. That being said, because of all the damage, you are going to have an ugly tree(s) for quite some time. IF these were my plants, I would re-pot into a larger pot, perhaps 4" wider, and get some new growth started. When you re-pot, check and see if there are separate plants or if all these stems come from one "trunk". After I saw good top-growth on each stem, I would then either air-layer those stems, or simply cut them about 18" above the soil-line so that new growth/branches will begin at that point. By air-layering, you have the option of being able to pot-up those tops when roots form. I would guess that spring/early summer is when air-layering/trimming would take place.
Let me know when you re-pot and find out how many plants are actually in this single pot. Knowing this can slightly alter my thinking on the air-layering/trimming.
Good luck. By the way, please go to your "Profile" (click on the little fella in the upper right-hand corner) and insert your location, USDA zone and city/state. That way, when you post, your location will always show. Knowing location is important when asking or answering questions.