Step 1: Bromination (Electrophilic Aromatic Substitution)

Reagent: Br₂ / FeBr₃
Reaction name: Halogenation

• NO₂ is meta-directing
• Bromine enters meta position

Product: m-bromonitrobenzene

Step 2: Reduction

Reagent: Sn / HCl
Reaction name: Reduction of nitro group

• NO₂ → NH₂

Product: m-bromoaniline

Step 3: Neutralisation

• Converts salt to free amine

Step 4: Bromination in water

Reagent: Br₂ / H₂O
Reaction name: Bromination of aniline

• NH₂ is strongly activating → ortho & para substitution
• Already one Br present → total becomes 3 Br added

Product: tribromoaniline derivative

Step 5: Diazotization

Reagent: NaNO₂ / HBr (0-5°C)
Reaction name: Diazotization

• NH₂ → N₂⁺

Step 6: Sandmeyer Reaction

Reagent: CuBr / NaBr
Reaction name: Sandmeyer reaction

• N₂⁺ → Br

Final Product (P):

• Initially 1 Br
• After step 4 → +3 Br = 4 Br
• After Sandmeyer → +1 Br

Total bromine atoms = 5

Final Answer:

Number of bromine atoms = 5