Within reasonable limits yes most plants can be potted into a smaller pot. But you will have to root prune it quite hard depending how much smaller you want to get. Can you post a picture of the plant with the pot and also tell us the current pot size and how much smaller you want to go?

Are you also planning to keep it indoors all year round? How much light do you get where the plant is?

Small pot and plant that wants to naturally grow large poses a few challenges. Much like doing bonsai which is the art of growing in a small container. All those challenges can be overcome but you will have to invest some time absorbing the details making a plant thrive in limited space.

The current soil is probably a peat based mix and the plant will eventually suffer in that mix due to compaction, lack of air and too much water. If you want to keep it healthy you will need to invest in a good potting mix. One my indian banyan is in a bark based mix. It is called 511 mix. To learn more about it you can read this post by Al.

https://www.gardenweb.com/discussions/2842847/container-soils-water-movement-and-retention-xxii

You'll also find this info about long term care of containerized trees in pots to be useful.

Al