In a family there are six members A, B, C, D, E, F. A and B are married couple. D is only son of C. A is father of E, who is granddaughter of F, whose husband has died and C is brother of A. How many male members are in the family?

Let's decode the relations step-by-step:
1. $A$ and $B$ are a married couple.
2. $A$ is the father of $E⟹A$ is Male, so $B$ must be Female.
3. $E$ is the granddaughter of $F$, whose husband has died $⟹F$ is a widowed Female.
4. $C$ is the brother of $A⟹C$ is Male.
5. $D$ is the only son of $C⟹D$ is Male.
6. Since $E$ is the granddaughter of $F$, and $A$ and $C$ are brothers, $F$ is the mother of $A$ and $C$.
7. $E$ is a granddaughter $⟹E$ is Female.

Now, let's list the genders of all 6 members:

* Males: $A$, $C$, $D$ (Total = 3)
* Females: $B$, $F$, $E$ (Total = 3)

Thus, there are 3 male members in the family.