The electronic and magnetic properties of 6H-SiC with Mn impurities have been calculated using generalized gradient approximation formalism. Various configurations of Mn sites and Si and C vacancies were considered. It was found that 6H-SiC doped with Mn atoms possess a moment for both types of substitution. The Mn atom at Si site possesses larger magnetic moment than Mn atom at C site. The energy levels appearing in the band gap due to vacancies and due to Mn impurities are determined and the calculated densities of states are used to analyze the different values of the magnetic moments for different types of substitution. A model that explains the magnetic moment at Mn site is proposed. (C) 2013 American Institute of Physics.