In Wurtz reaction, n-hexane is obtained by

 Wurtz reaction is a coupling reaction due to this alkyl groups of reactants get doubled.

Balanced chemical reaction 

2 ${\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2-\mathrm{Cl}+2\mathrm{Na}\to {\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_3+2\mathrm{NaCl}$.

So, n-hexane is obtained by n-Propyl chloride.