Section 2(77) of Companies Act, 2013 read with Rule 4 of Companies (Specification of definitions details) Rules, 2014 - A person shall be deemed to be the relative of another, if he or she is related to another in the following manner, namely:-
(1) Father:
Provided that the term “Father” includes step-father.
(2) Mother:
Provided that the term “Mother” includes the step-mother.
(3) Son:
Provided that the term “Son” includes the step-son.
(4) Son’s wife.
(5) Daughter.
(6) Daughter’s husband.
(7) Brother:
Provided that the term “Brother” includes the step-brother;
(8) Sister:
Provided that the term “Sister” includes the step-sister.
Therefore mother's brother and sister or father's brother and sisters will not be considered as "relative" for appointment as statutory auditor purpose.