The relation is father and daughter. As we go with male gender, will be son of A. But it is given in the question that B is not the son of A. Hence, te only possile is B is female and B is daughter of A.

A is a male and married to B. So, A is the husband and B is the wife. C is the brother of A. D is the son of C. E, who is the sister of D will be the daughter of C. B is the daughter-in-law of F whose husband has died means F is the mother of A. 

A is a male. B. the wife, is female. C. the brother, is male. D. the son, is male. E, the sister, is female. F, the mother, is a female. So, there are three males. 

Man's son's sister ? Man's daughter. So, the man's daughter is the mother of the woman's husband 

Thus, the woman's husband is the grandson of the man in the photograph. 

Brother of uncle's daughter ? Uncles son ? Cousin.

So, the man is Seema's cousin. 

T is the brother of S, who is the daughter of R. So, T and S are the children of R. 

Now. Q is the brother of R. So, T and S are the cousins of Q. 

Q is the son of R but R is not the mother. So, R is the Father of Q. P is married to R 

So, P is the wife of R and the mother of Q, X is the daughter of P and hence of R and so she is the Sister of Q, Y is the brother of R and Z is the brother of P. 

Clearly, Q is the son of P and X is the daughter of P. So, P has two children. 

Daughter of your mother's father's mother => Maternal grandmother => Renu's Aunt.

Hence, Laxmi is Renu's Aunt and Vishal is Renu's Uncle.

K is the father-in-law of H means H is the wife of the brother (say, J) of the daughter (say, L) of K and K is a male (brother or father of some person, say P) i.e H @ J $ L # K $ P or H @ J $ L # K & P.

Clearly, F is the maternal uncle of D means F is the brother of D's mother i.e., F is the brother of C. C is the sister of B. 

So, F is the brother of B who is A's mother. Thus. F is the maternal uncle of A. So, A and D are the nephews of F i.e., F has two nephews