Marry a cousin

Aunt is a vague term, whether she is your bua, chahi or any other relation ?

In any case the same comes under prohibited under the provisions of Section 3(c) to 3 (f) of the HMA, 1955 which reads as:

(c) “full blood” and “half blood”— two persons are said to be related to each other by full blood when they are descended from a common ancestor by the same wife and by half blood when they are descended from a common ancestor but by different wives;

(d) “uterine blood”— two persons are said to be related to each other by uterine blood when they are descended from a common ancestress but by different husbands;

Explanation. —In clauses (c) and (d), “ancestor” includes the father and “ancestress” the mother;

(e) “prescribed” means prescribed by rules made under this Act;

(f) (i) “ sapinda relationship” with reference to any person extends as far as the third generation (inclusive) in the line of ascent through the mother, and the fifth (inclusive) in the line of ascent through the father, the line being traced upwards in each case from the person concerned, who is to be counted as the first generation;

(ii) two persons are said to be “sapindas” of each other if one is a lineal ascendant of the other within the limits of sapinda relationship, or if they have a common lineal ascendant who is within the limits of sapinda relationship with reference to each of them;

(g) “degrees of prohibited relationship”— two persons are said to be within the “degrees of prohibited relationship”—

(i) if one is a lineal ascendant of the other; or

(ii) if one was the wife or husband of a lineal ascendant or descendant of the other; or

(iii) if one was the wife of the brother or of the father's or mother's brother or of the grandfather's or grandmother's brother of the other; or

(iv) if the two are brother and sister, uncle and niece, aunt and nephew, or children of brother and sister or of two brothers or of two sisters;

Explanation .—For the purposes of clauses (f) and (g), relationship includes—

(i) relationship by half or uterine blood as well as by full blood;

(ii) illegitimate blood relationship as well as legitimate;

(iii) relationship by adoption as well as by blood;

and all terms of relationship in those clauses shall be construed accordingly.

Give clarity as pointed by sri Vashista ji..

In South India (TN, AP, Telangana) marrying a paternal aunt's children is the first preference.  It all depends on your traditions and past practices in your family.

Such marriages fall within the prohibited degree unless sanctioned by the custom established in the community.

As rightly observed by expert Mr. Prasad, the marriage between the girl and boy belonging to brother and sister respectively can marry each other, there is no restriction in that aspect in Tamilnadu, Andhra Pradesh, Karnataka State etc. 

However some North Indian states oppose to marriage between such relationship.

Thus you may confirm that if your caste customs or the customs of your society accepts this relationship then you can go ahead with the proposed marriage if not then you may have no choice than to ignore