Some average characteristics of light nuclei produced in pC, dC, 4HeC, and 12 CC- interactions at 4.2 A GeV/c, are studied as a function of centrality. The centrality is fixed by the number of identified protons. The experimental data is taken from 2m propane bubble chamber installed at LHE (JINR), Dubna. Experimental results are compared with the results calculated from the simulated data of two Monte-Carlo event generators; Fritiof model and Cascade Evaporation Model. With increasing the mass of projectile, both the models describe the behavior of average multiplicity of light nuclei well, whereas the average momentum and average transverse momentum are badly described by the models. However, in 12 CC-interactions, systematical deviation of average multiplicity of light nuclei from the model predictions is observed in central events. The behavioral change in average multiplicity, average momentum, and average transverse momentum are observed in same interval of centrality in 12 CC-interactions. This change and deviation from models are suggested as some signals of nuclear coalescence effect.