In strict Legal terminology, annulment refers only to making a voidable marriage null; if the marriage is void ab initio, then it is automatically null, although a legal declaration of nullity is required to establish this.
Annulment is a legal procedure for declaring a marriage null and void. With the exception of bigamy and not meeting the minimum age requirement for marriage, it is rarely granted. A marriage can be declared null and void if certain legal requirements were not met at the time of the marriage. If these legal requirements were not met then the marriage is considered to have never existed in the eyes of the law. This process is called annulment. It is very different from divorce in that while a divorce dissolves a marriage that has existed, a marriage that is annulled never existed at all. Thus unlike divorce, it is retroactive: an annulled marriage is considered never to have existed.
Grounds For Annulment
The grounds for a marriage annulment may vary according to the different legal jurisdictions, but are generally limited to fraud, bigamy, blood relationship and mental incompetence including the following:
1) Either spouse was already married to someone else at the time of the marriage in question;
2) Either spouse was too young to be married, or too young without required court or parental consent. (In some cases, such a marriage is still valid if it continues well beyond the younger spouse's reaching marriageable age);
3) Either spouse was under the influence of drugs or alcohol at the time of the marriage;
4) Either spouse was mentally incompetent at the time of the marriage;
5) If the consent to the marriage was based on fraud or force;
6) Either spouse was physically incapable to be married (typically, chronically unable to have s*xual intercourse) at the time of the marriage;
7) The marriage is prohibited by law due to the relationship between the parties. This is the "prohibited degree of consanguinity", or blood relationship between the parties. The most common legal relationship is 2nd cousins; the legality of such relationship between 1st cousins varies around the world.
8) Prisoners sentenced to a term of life imprisonment may not marry.
9) Concealment (e.g. one of the parties concealed a drug addiction, prior criminal record or having a s*xually transmitted disease)
Basis Of An Annulment
Point 1. I am presuming that the following conditions were satisfied: Further in your second reply you tell she is a divorcee, was it a legal divorce(approved by the court) at the time of the marriage or was the divorce proceedings in process. The non fullment can lead to annulation of the marriage.
(i) neither party has a spouse living at the time of the marriage;
(ii) neither party is an idiot or a lunatic at the time of the marriage;
(iii) the bridegroom has completed the age of eighteen years and the bride the age of fifteen years at the time of the marriage;
(iv) the parties are not within the degrees of prohibited relationship, unless the custom or usage governing each of them permits of a marriage between the two;
(v) the parties are not sapindas of each other, unless the custom or usage governing each of them permits of a marriage between the two;
(vi) where the bride has not completed the age of eighteen years, the consent of her guardian in marriage, if any, has been obtained for the marriage.
Point 2. : Going by the details of your query, I presume according to Hindu rites you meant the following rites were conducted
Ceremonies for a Hindu marriage.- (1) A Hindu marriage may be solemnized in accordance with the customary rites and ceremonies of either party thereto.
(2) Where such rites and ceremonies include the Saptapadi (that is, the taking of seven steps by the bridegroom and the bride jointly before the sacred fire), the marriage becomes complete and binding when the seventh step is taken.
If the above points are considered then incase of a void marriage you can be granted annulment.