We viewed your photos. The houseplant looks like a type of Dracaena. The foliage shows some fungal leaf spots. You can also check the leaf undersides for spider mites, a sucking insect. http://extension.umd.edu/hgic/plants/spider-mites-houseplants
All you can do is pick off the affected individual leaves, decrease leaf wetness or increase air circulation will help to lessen the chances of infection. Watering should be done early in the day to allow leaf surfaces time to dry quickly. Make sure the containers have holes for good drainage.
Fungicides will not cure any affected leaves. They protect unaffected foliage only. It is possible that you may have to buy a new plant. Focus on proper care.