Ficus elastica

Question

When is the best time to re-pot?

Answer 1

You can repot your plant when the roots are filling the entire pot.
You should only go up 1 or 2 inches in pot size and use a good quality potting mix.

https://www.gardeningknowhow.com/houseplants/rubber-tree/how-to-care-for-a-rubber-tree-plant.htm