Step 1: Track the directing effect through resonance structures for the first substitution.
Nitration of benzene gives nitrobenzene, and the $-NO_2$ group withdraws electron density from the ring by resonance, leaving the ortho and para positions most electron poor and the meta position comparatively electron rich. Because of this, any further electrophilic substitution is pushed to the meta position.
Step 2: Apply this to the chlorination step.
With $Cl_2/AlCl_3$ acting as the electrophile source on nitrobenzene, the incoming chlorine has to go to the position left most electron rich by the nitro group, which is the meta position, giving meta-chloronitrobenzene.
Step 3: Reduce the nitro group and see how the directing power flips.
Catalytic hydrogenation with $H_2/Pd\text{-}C$ converts $-NO_2$ into $-NH_2$. Unlike $-NO_2$, the amino group is a powerful electron donor by resonance, so it strongly directs new substitution to the ortho and para positions relative to itself, the opposite behavior of the group it replaced.
Step 4: Work out where the chlorine now sits relative to the new amino group.
Since the chlorine was installed meta to the original $-NO_2$ position, once that same position becomes $-NH_2$, the chlorine ends up sitting ortho to the amino group in the final ring.
Step 5: Confirm this gives the expected product.
An amino group at one position with a chlorine ortho to it is exactly the substitution pattern of ortho-chloroaniline, matching the major product expected from this three step sequence.
Step 6: Final answer.
\[ \boxed{\text{o-chloroaniline}} \]
