why is my rubber tree losing its leaves?
Rubber trees are rather fragile and loose their bottom leaves for a number of reasons.
If you leave the tree alone the tree will become tall and spindly and branches will begin to grow from its bare trunk. Usually these trees eventually get so weak that they can't support themselves and need stakes to hold them up or need to lean against a wall.
Your other option is air layering where you make new roots on the stem then cut the top off and plant it.
put it outdoors water every 2 days heavily. lots of sun and enjoy the new growths. Do not over water!
Maybe it's deciduous