The law of succession under the Hindu Succession Act, 1956, is classified as under:

1. Testamentary succession:
   The law of testamentary is concerned with giving the best effect to the wishes of the testator.
    
2. Intestate succession:
   The law of intestate succession is concerned with the mode of devolution of property of the person dying intestate and heirs disqualified from inheritance.

The Act provides a detailed scheme of devolution of property by intestate succession for Hindus who are subject to the application of this Act. It abolishes the distinct laws of succession under the Dayabhaga and Mitakshara systems and provides a uniform law, based on natural love and affection, and nearness in a relationship. Under Hindu Law, the inheritance rights of a person were not absolute.

Despite the nearness of the relationship, a person could still be disqualified from inheriting property.

Disqualifications
The Hindu Succession Act, 1956 has simplified the Hindu law and reduced the disqualifications to the barest minimum. The present Act provides for three types of disqualifications only, which are based on a violation of the fundamental principles of inheritance.

1. Remarriage
2. Murderer
3. Conversion

Succession when Disqualified:

Section 27, Hindu Succession Act, 1956 lays down that "if any person is disqualified from inheriting any property under this Act, it shall devolve as if such person had died before the intestate."

It states that a person who is disqualified under this section is considered to be dead before the intestate. It means no title or right can be succeeded by the disqualified heir. For instance, P dies leaving behind two brothers A and B, and nephew AS, son of A. A is a disqualified heir. AS will not inherit anything. B will take the entire property.

1. Remarriage

   Section 24 has been omitted by the Hindu Succession (Amendment) Act, 2005. Under this section, remarriage of three widows, before succession opens disentitle them from inheritance. These windows are:
   
   • Son’s widow
   • Son’s son’s widow
   • Brother’s widow

   It was held in, Kasturi Devi v deputy div. commissioner,1976, that the widowed mother and widowed stepmother are not disqualified from inheritance even if they have remarried.
    

2. Murderer

   Section 25, Hindu succession Act, Disqualifies an heir who himself murdered or abetted the murder, in furtherance of succession:
   
   • Of propositus, or
   • Of someone other than the propositus.
   • It states that murder must be in "furtherance of succession".

   Under this section, the murderer, as well as the abettor of murder, are disqualified. For instance, P has two sons, A and B. A abets B to murder P. In this case both, A and B are not entitled to inherit the property. G.S. Sadashiva v. H.C. Srinivasan, 2001.
   
   In this case, an heir being a murderer was sought to be disqualified but in the event of the finding of the criminal court that the deceased had committed suicide and was not murdered, disqualification was not incurred. This section applies to both laws of succession i.e Testamentary and Intestate succession.
    

3. Conversion:

   Section 26, Hindu Succession Act states that conversion of an heir is not a bar to succession. This section disqualified the children of the convert and not the heir who has converted. Also, the children and descendants of the heir cannot inherit, unless such children or descendants are Hindus at the time when the succession opens.
   
   The succession to the property of the heir who has converted will be governed by the personal law of the community to which he has converted. For instance, succession to the property of Hindu converted to Islam will be governed by Muslim Law. We may illustrate the rule with the following example: P died leaving behind two sons. A and B and two grandsons CS, CS1; of a predeceased son C who had converted to Islam.
   
   All the two sons were born to C after his conversion. CS, CS1 are disqualified and will not take any property. A and B will take ½ each. Balchand Jairam Lalwani v. Nazneem Khalid Qureshi, 2018, The Court held that Disqualification under this section applies to the children of the convert and not to the child/heir who has converted. This section is only applicable to intestate succession and not to testamentary succession where the succession is governed by the testator.
    

4. Disease, Deformity, and Unchastity

   Section 28, Hindu Succession Act states that "No person shall be disqualified from succeeding to any property on the ground of any disease, defect or deformity, save as provided in this Act, on any other ground whatever" It means there would be no disqualifications on the grounds of any disease or deformity. Chandi v. Bhagyadhar, 1976, The court held that Disease, deformity, and unchastity are no longer disqualifications.

This section applies to both laws of succession i.e Testamentary and Intestate succession.

Conclusion
The Hindu Succession Act,1956 has undergone a lot of change by the Hindu Succession (Amendment) Act,2005, Section 24 which discriminated against women has been omitted by the Amending Act of 2005. Murderers or abettors of murder, children, and descendants of the heir of an intestate, have been disqualified under this act. A person can inherit the property unless he has been disqualified under these disqualifications.

References:

1. Diwan, Paras.(2019), “Succession.” Modern Hindu Law. Faridabad: Allahabad Law Agency.
2. https://legislative.gov.in/sites/default/files/A1956-30.pdf.
3. Kasturi Devi v. Deputy Div. Commissioner, AIR 1976 S.C.2595.
4. G.S. Sadashiva v. H.C. Srinivasan, AIR 2001 kant.453.
5. Balchand Jairam Lalwant v. Nazneem Khalid Qureshi, AIR 2018 Bom.103.
6. Chandi v. Bhagyadhar, AIR 1976 Cal.366.