Particle ratio fluctuations in Au–Au and Pb–Pb collisions at RHIC and LHC energies are studied using HYDJET++ model and the findings are compared with those reported for the real data. The variable \(\nu _{dyn}[a,b]\) is used for this purpose, which is suitable for fluctuations studies due to being robust against detector efficiency losses. It is observed that the \(\nu _{dyn}\) for pairs \([\pi ^{\pm }, K^{\pm }]\) and \([p\bar{p}, K^{\pm }]\) acquires positive values for all centrality classes showing anti-correlations between particle pairs and is in qualatative agreement with the data. For \([\pi ^{\pm }, p\bar{p}]\) pair too the model predicts anti-correlation for all centrality classes, while the experimental results show the presence of correlation for peripheral collisions and anti-correlation for semi-central and central collisions.