It could be that because it's not quite spring yet, you have a bit to wait until the leaves open. Continue taking good care of it, and when the climate changes a bit more, the leaves of your rubber tree should open.
Your tree needs more water. I adopted a rubber tree plant whose leaves were completely closed. I moved it in front of a South facing window - I live in Michigan and started to water it once overy other week. It took no time for the leaves to open and start growing again.Why won't my rubber tree plant's leaves open?
thanks SteveWhy is my rubber tree losing its leaves?