Don't fertilize it in wintertime. Make sure it's not sitting in water. Had it been growing in a greenhouse before you bought it? It's probably just responding to lower light levels...a change in environment. Hopefully it will stop dropping leaves and stabilize. Give it as much light as you can and don't overwater.

That’s the problem. You bought a Ficus to fill a corner. Ficus are high light loving plants. They need to be right up in front of your brightest window.

They will survive drought a lot better than they will survive being over watered. Check deep down in the soil before you water.

the brown leaf tips are a sign of over watering. Lack of light and too much water combined with a soil that doesn’t drain fast are the likely issues here.

Note: don’t fertilize in the winter is a myth. you can fertilize all year round and should. only exceptions are after repotting and or if the plant is struggling such as the one above. Then you should not.

its stressed not hungry ... no more fert ...

and dont fert it after repot ... until it settles from that stress ... at least a couple months ....

let it near dry between waterings ... it is a tree.. not a water loving plant ... insert finger and find out when its getting near dry ... and do check the bottom of the pretty pot ...

you might be loving it to death on some level.. just water properly ... and let it settle in ...

and if you can move it closer to the window ... all the better ... maybe move the dresser to the corner.. and put the plant in the window ...

it should probably go outside for summer ... to catch up on light loss ... plants convert sun into energy.. and store it the roots for later use ... but if you do move it outside full bright shade.. never straight into direct sun ...

i do prefer pot in pot... but you need a bigger nursery pot ... perhaps you can start looking for that in the meantime ...

never forget.. the most important thing in a pot.. is not the plant.. but the media you use ... tree prefer a sip of water.. and near total drainage ... not a media that holds lots of water for a long time ... you might research that int he meantime also ...

ken

Ficus are definitely one of my go to indoor trees. Most species are extremely adaptable to indoor home conditions. I have a Ficus alii (your species) as well. Your room does not look dark, but it would still prefer the location in front of that window to the left in your pic. As said above, no fertilizer now, it's not helping and may be hurting. Let it get quite dry before you drench it. I would also prune off the dead branches, those won't come back. However, don't be discouraged, Ficus are extremely resilient, my Australian banyan lost all its leaves last Winter due to my neglectful watering, I put it outside in the Summer and now its serves as my decorated X-mas tree once again. I will repot it next Spring and by the end of Summer it'll be up to the ceiling!

In 2019 my husband bought me a Ficus tree - not the same type as yours - for Valentine's Day... it dropped leaves like crazy and I was sure it was going to die. This past summer I decided to put it outside. It has absolutely thrived! It was shaded by my big table umbrella - if the sun hit it at all it burned. But the indirect light made it thrive.

It's back in the house now for winter and it's still looking good... I just hope it stays that way till next spring when I for sure will put it out again. If you're able to put it outside next spring give it a try!