It is not Mritu Shadashtak Yoga. It is just Shadashtaka. It is the Rashi sign compatibility which takes into account the Moon signs of the two individuals. Generally this is used in marriage compatibility and some times also to with reference to the suitability of partnership. In a marriage chart the rashi sign compatibility indicates growth of family, family welfare and economic conditions of the partner.
The negative effects of this yoga are reduced or ignored if moon sign lords are friends or if Moon sign lords are same. In the given example chart Female moonsign is Pisces and Male moonsign is Leo. Rashis of male and female in compatibility analysis are 6 - 8 with respective to each other causing Shadashtak. This shows difference of opinion, tension in the married life. But lords of the rashis are natural friends so no major problem indicating.