We present a study of centrality classes determination based on number of charged particles registered with the Time Projection Chamber (TPC) in Multi-Purpose Detector (MPD) at NICA complex. Precise determination of centrality classes will allow one to select ion collisions within a certain class based on the initial impact parameter in order to study behaviour of variables on the mean energy densities reached in the certain event classes. It is important to study the QCD matter produced in the collisions with respect to the geometric properties of the collision between nuclei, but these properties cannot be directly measured. Therefore, we analyze in this work the centrality classes which are obtained using different sets of selection criteria for centrality calculations, which include the number of hits in the TPC pseudorapidity window and transverse momentum of registered particles in the TPC sub-detector for Bi+Bi collisions at 7.7, 9, and 9.46 GeV generated by the Ultra relativistic Quantum Molecular Dynamics (UrQMD) model.