Can you house a red eared slider with a mississippi map turtle?

Yes, every thing should be fine just watch them and make sure that they get along. Also, understand that these turtles will get large(Red Eared Sliders get 10-12in and male Mis. maps get about 5in while female Mis. maps get 10in) so you will need to keep them in a 150gallon plus tank or backyard pond. Hope every thing works out!