In this paper, we consider a problem of simultaneous global cost minimization and Nash equilibrium seeking, which commonly exists in N -cluster non-cooperative games. Specifically, the agents in the same cluster collaborate to minimize a global cost function, being a summation of their individual cost functions, and jointly play a non-cooperative game with other clusters as players. For the problem settings, we suppose that the agents' local cost functions can be non-smooth, the explicit analytical expressions are unknown, but the function values can be measured. We propose a gradient-free Nash equilibrium seeking algorithm by a synthesis of Gaussian smoothing techniques and gradient tracking. Furthermore, instead of using the uniform coordinated step-size, we allow the agents to choose their own specific constant step-sizes. When the largest step-size is sufficiently small, we prove a linear convergence of the agents' actions to a neighborhood of the unique Nash equilibrium under a strongly monotone game mapping condition, with the error gap being propotional to the largest step-size and the heterogeneity of the step-size. Moreover, we provide both upper and lower bounds for the rate of convergence of the proposed algorithm. The performance of the proposed algorithm is validated by numerical simulations.