It is not possible to tell which grass blend you have from these photographs. There appears to be some tall fescue as well a grass that could be fine fescue or rye grass but these are not reliable ids. There may be more in the mix as well.

Your best course would be to choose a mixture that will do well in the area.  Cornell Cooperative Extension's Turf Program has a good guide to the grasses and grass blends that perform the best in particular conditions of sun: http://turf.cals.cornell.edu/lawn/lawn-care-the-easiest-steps-to-an-attractive-environmental-asset/starting-fresh/choose-seed/