Answer is Manganese(ii) chloride
To answer this, you need to know the charges for both Mn and Cl
Mn is in the transition metal category and is unique with having 3 levels of charges
manganese - MN
Manganese(ii) - Mn^2+
Manganese(iii) - Mn^3+
Cl is a nonmetal with the standard charge of Cl^-1
Since you have two charges that don't cancel out, they get switched.
So Cl would receive a positive 2. Because it was a positive 2, we can assume that it starts with Manganese(ii). Then we add chloride to the end of it as it ends with Cl.