The (n, 2n) reaction cross section calculations for some neighbouring target nuclei either with deformation or without deformation have been made for an incident energy range of 8 - 24 MeV. In these calculations, the geometry dependent hybrid model and the exciton model consisting of the effects of pre-equilibrium emissions have been used. The exciton model has also been used to investigate the pre-equilibrium direct effects. Furthermore, the experimentally measured cross sections taken from literature have been calculated using other empirical and the semiempirical formulae for the incoming energies which satisfy the condition U-R + E-n + Q(n,2n) = 6 +/- 1 MeV. The theoretical and experimental results for some neighbour target nuclei with or without deformation have been compared. The obtained results have been discussed with the available experimental data, and found to be good in agreement.