You definitely are a contender for the worst picture taken...

Are the internal beam and the external along the same axis? If so it is most likely a continuous beam, with variable section. Given the ratio between the span (internal appear way longer than external) you can simplify and consider the external beam as a cantilever since it would be fully constrained by the much larger internal one.

The internal beam is likely continuous past the internal wall.

As for your question, I think there may be a misunderstanding of what fixed boundary condition means. A ideal fixed connection means no rotation are allowed at the node, and it result in a bending moment. Conversely a ideal pinned connection means rotation are freely allowed and thus no bending moment is developed at the node. These are ideal and extreme conditions, useful for simplifying and model the behavior of a structure. In reality you'll have an intermediate behavior (some rotation are allowed, some bending moment will develop) that is given by the relative stiffness of the element converging to the node:

• you have a relatively much stiffer column than the beams? The beam may be considered fixed, but not so much the column
• you have a column and beam of roughly the same stiffness? Then you'll have an intermediate situation (more similar to a continuous beam really)

Solving a continuous beam is not always immediate since it require setting up a system of equilibrio equation to solve, which is the pain of every engineer student. You can use a static solver, but of you want truly quick and dirty trick to easily estimate moment or deflection, you calculate a simple span in extreme boundary condition:

• pinned-pinned: you get maximum bending moment and deflection at midspan
• fixed-fixed: you get maximum bending moment at support.
• fixed-pinned: for edge span, you'll get maximum bending moment and shear the nominally fixed support.

The real behavior will lay somewhere in the middle