Legal heirship advice as per India muslim law

Even though the two daughters got cash and some other property from (sister of Grand Mother), they are entitled to the shares in the property as per the calculations of sharers and residuary of Mohd. Law.  But you can get registered release deed from your sisters by paying some more money (or whatever they have taken by way cash can be adjusted towards their share).  It depends upon your and convincing and persuading them. 

Since Mohd. Law Succession is very complicated and it needs elaborate calculations, I cannot give my exact answer to your query regarding succession.  But for the time being I am giving you the following table.  If you are more serious about the issue, you can contact me through Kaanoon.com.  I will help you.  

Father –1/6
Mother –1/6 
The rest 4/6th share will be divided into 10 parts. Four sons will take eight parts and two Daughters will take two parts (i.e. one part each). 

Note:--Sons will get double the share than daughters. 

HI 
a) Under muslim law, Males and females have equal rights of inheritance. Upon the death of a Muslim, if his heirs include also the females then, male and female heirs inherit the properties simultaneously. Males have no preferential right of inheritance over the females, but normally the share of a male is double the share of a female.
In other words, although there is no difference between male and female heir in so far as their respective rights of inheritance is concerned but generally the quantum of property inherited by a female heir is half of the property given to a male of equal status (degree).

b) The principle that normally the share of a male is double the share of a female has some justification. Under Muslim law, while a female heir gets (or hopes to get in future) an additional money or property as her Mehr and maintenance from her husband, her male counterpart gets none of the two benefits. Moreover, the male heir is primarily liable for the maintenance of his children whereas, the female heir may have this liability only in an extraordinary case.

c) In india under muslim law there is no recognition of  doctrine of representation. 
- That is to say in your case, Children of M, A and N will not get any share of the property. 
Rationale : Under muslim law, there can be no claim through a deceased person in whom no right could have been vested by any possibility. But, this stand of has been criticized by several mullah's and it is true that  non-recognition of principles of representation under the Muslim law of inheritance, seems to be unreasonable. It is  unreasonable  that a son, whose father is dead, is unable to inherit the properties of his grandfather together with his uncle.

d) However under sunni law you can divide the property in to 6 parts . then you can adjust the cash payment made to the daughters. 
After adjusting the cash payment to daughters, you can balance the properties in to 6 parts so that M, R, A, K , D and N get their respective shares without any ill bearing or ill will. 
Hope this helps.

on demise of grand mother her property would devolve on legal heirs as per muslim personal law 

2) As per to Sunni Sect the son always gets twice that of the daughter thus the ratio is 2:1.

3) daughters will be entitled to claim share in mother property 

4) even if any share was given to grand ma sister to daughter then also daughter would be entitled to claim her share in property of her mother 

1. The son always gets twice that of the daughter thus the ratio is 2:1. An Indian Muslim inheritance is considered as an integral part of Shariah Act of 1937. Under the customary Muslim law, a person cannot bequeath more than one-third of his property by will. Blood relationship (nasab) Asaba rights of inheritance arise only from blood relationship and not from relationship by affinity or by fosterage. In the traditional Sunni law, the family group knitted together by the web of social rights and obligations was the extended agnatic family of males linked through males to a common ancestor. Although maternal relatives do have rights of inheritance the main emphasis lies on the paternal connection and indeed the primary significance of the word nasab is that of paternity.

2. Legitimacy of birth is the legal postulate for admission to the family group. Illegitimacy precludes the existence of any legal bond between the blood relatives of the fathers on the one hand an the illegitimate child and its issue on the other. But if he has married under Special Marriage Act, then he can will away entire property, and succession is governed by Indian Succession Act, and not the Muslim personal law i.e. Shariah Act 1937.

The Muslim Personal(shariat) Application Act, 1937 will be applicable for the laws of succession governing Muslims intestate or non-testamentary disposition of  properties. 
For the purpose of inheritance Muslim law  does not make any distinction between corpus and usufruct or  movable and immovable or corporeal or incorporeal property.
Whenever a Muslim dies his properties  devolve on his heirs in definite shares of which each heir becomes a absolute owner of his share.  Subsequently upon the death of the shareholder his legal heirs get the shares and so on. 
Under Muslim law of inheritance no distinction is made between self acquired property or ancestral property. All properties whether acquired by a Muslim himself or inherited by his ancestors are regarded as individual properties and may be inherited by his legal heirs.  
Muslim law of inheritance does not recognise the concept of right by birth in the property.
Allah commands you regarding your children. For the male a share equivalent to that of two females. [Quran 4:11]
This first principle which the Quran lays down refers to males and females of equal degree and class. This means that a son inherits a share equivalent to that of two daughters, a full (germane) brother inherits twice as much as a full sister, a son’s son inherits twice as much as a son’s daughter and so on.
If there are any sons the share of the daughter(s) is no longer fixed because the share of the daughter is determined by the principle that a son inherits twice as much as a daughter. In the absence of any daughters this rule is applicable to agnatic granddaughters (son's daughters). The agnatic granddaughter has been made a Quranic heir (sharer) by Muslim jurists by analogy.
Inheritance is an important branch of the family law of the Muslims. The death of a person brings about a transfer of most of his rights to persons who are called his heirs and representatives. The transferable rights include all rights to property, usufruct, many dependant rights, such as debts and [unrecognisable word] in action, rights to compensation, etc., and the transmissible obligations are those capable of being satisfied out of the estate of the deceased. What is left after the payment of funeral expenses and the discharge of his debts and obligations is to be distributed according to the law of inheritance.

The rules regulating inheritance are based on the principle that the deceased's property should devolve on those who by reason of consanguinity or affinity have the strongest claim to be benefitted by it and in proportion to the strength of such claim. According to the Sunni law, the expectant right of an heir-apparent cannot pass by succession to his heir, nor can it pass by bequest to a legatee under his Will, nor can it be the subject of transfer of release.
The Sunni law recognises three classes of heirs:

(1) Ashabul faraiz --The sharers whose shares or proportions have been fixed in the Quran. They take their specific portions and the residue is then divided among the Agnates.

(2) The Asabah or Agnates, also called by English writers as Residuaries.

(3) Dhauil-arham or Cognates or Uterine Relations. They are also called Distant kindred i.e. relations who do not fall in the category of sharers or Agnates.

1) children of A and N will not get any share in property 

2) on grandmother demise only R , k being the surviving sons and daughter D would be legal heirs 

3) unknown in sharee’ah for a grandson to take the share of his deceased father, who would have taken it if he were alive.

 Rather the estate is to be shared out among the heirs who are alive at the time of their benefactor’s death. 

Inheritance is an important branch of the family law of the Muslims. The death of a person brings about a transfer of most of his rights to persons who are called his heirs and representatives. The rules regulating inheritance are based on the principle that the deceased's property should devolve on those who by reason of consanguinity or affinity have the strongest claim to be benefitted by it and in proportion to the strength of such claim.
My opinion to your latest query is that the referred heirs may fall under the category of 3rd item mentioned in  my previous answer, hence they may become eligible to a share as distant kindred heirs.