The pot is way too big for this: it is most likely in peat, so will stay wet longer and roots will rot.
you need to put the pot on it's side and very gently try to shake the root ball out to see the state of the roots. If you do not see lots of white roots at the sides and bottom, remove the extra soil that does not have dense roots and put the plant in a smaller pot. Hard to judge by the picture, but it seems the current pot is larger then 6".
do not try to remove soil between the roots: the less you mess with them the better. Granted, some roots will get damaged, but try not to play with them at this point.
There are different Caladium varieties, from very large to quite small.
When soil stays too wet with few roots it might even rot the tubers.
try to keep it very warm, preferably in western window close to the window where it can get long warm end-of-day sun. that would be best for indoors: they definitely need 3-4 hours of direct sun to grow well. Temperature matters a lot: 75-80F is best.
