Energy level statistics of a system consisting of six particles interacting by delta force in a two- model coupled with a deformed core is studied in particle-rotor model. For single- shell and two- shell the exact energies for our statistical analysis are obtained from a full diagonalization of the Hamiltonian, while in two- case the configuration truncation is used. The nearest-neighbor distribution of energy levels and spectral rigidity are studied as the function of spin. The results of single- shell are compared with those in two- case. It is showed that the system becomes more regular when single- space is replaced by two- shell although the basis size of the configuration space is unchanged. The degree of chaoticity of the system, however, changes slightly when configuration space is enlarged by extending single- shell to two- shell .
