I have two ficus ginseng with branches that I think are dead.

When I bought them I placed them too dark and they lost their leafs. I then placed them somewhere with sun and some of their leafs returned and they have been doing very well ever since. Except for some of the branches where the leafs won’t grow anymore. The branches have been leafless for 1 year+ So I thought that maybe it could help to cut the branches but I don’t know where to cut them. Can you guys help me

Hello!
Just cut the dead branches off, as long as the dead part extends, no mistery about that... I see you may have a balcony, when in spring and summer, place it outside if that's the case, and put it inside when winter begin to aproach, with danger of frost...

Just cut flush to the closest living branch.

Thank you @albas and @Tropfrog!

To make sure I do it right, would I cut along the blue line or the red lines on this picture ?

I would say by the blue, probably it's all dead...

However, if you want, you can cut that main branch closer and closer to the blue line until you find sap / living part (If it's alive), and stop there, but it is not guaranteed that the branch will survive due to sap retraction as we call here in Brazil (I don't know a proper translation)...

If there's no leaves on a certain branch, there's a probability that the tree will retract the sap flow, amputating the leafless part... (Mostly not for deciduous trees)

Perfect answer, thank you very much ❤️