Robots are now widely used around humans, in homes and public places like the museums, all due to their many benefits. These autonomous robots are called social or service robots and they always find it difficult to navigate in crowded environments; largely because of the high level of uncertainty in observing and predicting human behaviours in a highly dynamic environment. Uncertainty is propagated during prediction and might grow to levels that renders the whole environment unsafe for the robot leading to the socalled Freezing Robot Problem -FRP. This work presents our proposed approach to proactively account for various uncertainties during the robot's motion planning using a stochastic Nonlinear Model Predictive Controller (SNMPC). Additionally, using numerical optimization methods enables the planner to compute new control commands in realtime.