What is equivalents per mole?
The question can be understood as:
Which one of the following oxidants has a greater n-factor as there's only 1 mole each of permanganate ion and dichromate ion.

The n-factor of permanganate ion is (7-2)=5

while 

The n-factor of dichromate ion is (6*2-3*2)=6

So, the answer is the 2nd reaction.