hello,

Migration certificate, mark sheet and tc are issued by the board which the you may get from the school through which you were registered as private student. In case of character certificate, the board do not issue the certificate. In case of regular schooling the school issues the character certificate, but in case of private  stiudies, school do not issue as you were not in their school through out the year and they do not know about you, what you were doing through out the year. In such case character certificate is issued from the respective tahsil or by the any gazetted officer who know you during the year.

hope this helps!!