To confer clear and marketable title to property registered sale deed is must 

2) POA does not confer title to property 

3) ask the seller to execute registered sale deed in your favour 

The supreme court has ruled that property transfers through poa cannot create ownership rights ie a person cannot sell the land unless he has transferred it in his name. Therefore transfer the property in your name through the person who originally had tge property.

Regards 

See now to claim the property either the original owner execute a registered deed in favor of your the legal heirs of grand parents or in case they are not available a suit of declaration is to be filed.

- Property inherited by a Hindu from his father, grandfather or grandfather's father, is ancestral property.

- The grandson's right to a share in thisproperty accrues by birth itself.

- Hence, If the said property is not disputed , then all the legal heirs have equal right in the said property.

Dear Sir,

After the death of your  grand father it naturally devolves on the following formula

Section 8 in The Hindu Succession Act, 1956

1. General rules of succession in the case of males.—The property of a male Hindu dying intestate shall devolve according to the provisions of this Chapter—

(a) firstly, upon the heirs, being the relatives specified in class I of the Schedule;

(b) secondly, if there is no heir of class I, then upon the heirs, being the relatives specified in class II of the Schedule;

(c) thirdly, if there is no heir of any of the two classes, then upon the agnates of the deceased; and

(d) lastly, if there is no agnate, then upon the cognates of the deceased.

Hindu Succession Act, 1956 [Section 8]

HEIRS IN CLASS I AND CLASS II

CLASS I

Son; daughter; widow; mother; son of a pre-deceased son; daughter of a pre-deceased son; son of a pre-deceased daughter; daughter of a pre-deceased daughter; widow of a pre-deceased son; son of a pre-deceased son of a pre-deceased son; daughter of a pre-deceased son of a pre-deceased son; widow of a pre-deceased son of a pre-deceased son.

CLASS II

1. Father.
2. (1) Son’s daughter’s son, (2) son’s daughter’s daughter, (3) brother, (4) sister.

III. (1) Daughter’s son’s son, (2) daughter’s son’s daughter, (3) daughter’s son, (4) daughter’s daughter’s daughter.

1. (1) Brother’s son, (2) sister’s son, (3) brother’s daughter, (4) sister’s daughter.
2. Father’s father; father’s mother.

VI.. Father’s widow; brother’s widow.

VII. Father’s brother; father’s sister.

VIII. Mother’s father; mother’s mother.

1. Mother’s brother; mother’s sister.

Explanation : In this Schedule, references to a brother or sister do not include references to a brother or sister by uterine blood

Even if there is no power of attorney you can go to court as legal heir and get declaration from court. You can also go for sucvession certificate if required

It must be POA with consideration, irrevocable and registered. There must be clause in POA of successor ship that on the death of POA holder, POA shall vest in his legal heirs.

Apply for legal heir certificate and On the basis of POA and LHC execute sale deed in favor of legal heirs.

1.  IF Grand Parents have not executed a WILL document, THEN apply for "Letter of Administration" (LA) in the Delhi high court, and based on the LA, you can apply for change in Mutation Entry, in the colony records with the Tahsildar /Municipal /Society /Association offices, by following due procedure of law.  There is no need for further POA in this matter.

Dear Client,

You may move an application in the court to issue a legal heir certificate to you. 

You need to file a civil suit in this regard and let the court decide the ownership of the property as soon as you get the degree from the court you can get the property transferred in your name

contact seller to execute sale deed in your favour. 

First of all transfer of property should be done by using the power of attorney of the seller in name of legal heirs.

After that the share can be distributed among legal heirs through settlement deed.