where does kmeans store its trained model parameters in scikit learn? Like in linear regression, there is model.intercept_ and model.coef_ but in kmeans i found  kmeans.inertia_ , I dont know what is that.
K-means stores 4 model parameters namely cluster_centers_, labels_, inertia_, n_iter_. For details on what they store you can look at the official documentation. Also, Inertia, or the within-cluster sum of squares criterion, can be recognized as a measure of how internally coherent clusters are. You can see a full description here under the section: 2.3.2. K-means.