What would be the maximum number of emission lines for atomic hydrogen that you would expect to see with the naked eye if the only electronic energy involved are those as shown in the figure?

If the only number of electronic levels involved in the transition are those depicted in the figure, we would like to know how many emission lines for atomic hydrogen can be seen with the unaided eye. The hydrogen atom's spectrum has six electronic levels, as stated. Only if the transition lines are in the visible region can one observe the emission lines for the electron transition.
We are aware that only the transition lines in the Balmer series, out of all the transition series produced by an electron transition, are located in the visible spectrum.
When an electron transitions from one of the higher energy levels to the second energy, the Balmer series transition lines are produced.

level known as $\mathrm{n}= 2$.
The electrons from the energy levels n=3, n=4, n=5, and n=6 can undergo transition to create emission lines in the Balmer series, as can be seen from the depicted atomic hydrogen spectrum.
The transitions that produce the emission lines that are visible to the naked eye are $3\to 2$, $4\to 2$, $5\to 2$, and 6. As a result, the presented spectrum of atomic hydrogen has 4 emission lines that can be observed with the naked eye.