As you may have gathered from the responses above, salt isn't something that usually has a place in freshwater aquaria.
I can sympathise with the question, as I remember a time when some keepers swore by adding some salt to all of their tanks for almost all of their fish, but it's very old advice now. I have heard it recently, but it's not generally a good idea.
Most freshwater fish can tolerate a small amount of salt in the water, some quite a lot, some none at all. Cories are regarded as being in the none at all group by the way, so the answer to your question is no regardless. It can be used as a medication, and as a stabiliser for nitrite problems, but it's place in a standard freshwater aquarium is quite rightly limited.