Rubber Tree plants can get very large with proper care. They thrive with neglect and do not mind at all if you stick them in a dark corner.
A Rubber Tree does best with medium light and medium damp soil. Keep them away from direct light and away from drafty windows. Water them when the top inch or so of soil is dry when you press your finger into it.
You can prune it back when it gets too large by cutting off the tips of the stems. It will get bushier and fill out nicely if you do this.
In the wild these trees can get 60m tall, but usually stop at 30m-40m. It will grow outside in frost free areas. It does not like extreme heat. It does like humidity.
Rubber tree sap ( latex ) can cause severe allergic reactions in some people.