definition

Kindly refer the defination of relative as per section 2(77)

relative with reference to any other person means any one who is related to another if :

they are members of Hindu undivided family

they are husband and wife

one person is related to other in such a manner as may be prescrbed

any other person as may be prescribed is given as per Rule 4 of Company specification Rules.

it includes :

Father (including step father)

Mother (including step mother)

Son

Son's daughter

daughter's husband

brother(including step brother)