Hopefully your rabbit's foot fern is already planted in a 6 to 10 inch container filled with all purpose potting soil and amended with peat to retain moisture. A plastic container is preferable to a clay one because it is slower to dry out.
Make sure your fern is positioned in an area with bright indirect light...an indoor northern exposure is ideal. Also, moderate temperatures are best as high heat can burn the fronds.
Be sure to water your fern thoroughly, making sure that the container drains well. Rabbit's foot likes moist--not soggy--soil. Water it when the top of the soil begins to dry slightly.
Dilute water soluble fertilizer to 1/4 strength and feed twice a month.
Check for pests periodically. Remove them with cotton swabs dipped in alcohol or plain water.
Hopefully, following these steps will enable your rabbits foot fern to grow healthy new foliage.