The assets immovable and movable belong to a person's legal heirs if he dies intestate. In you case after your father's death the property belongs to his children and his wife and not his father. He cannot claim to be a legal heir.

No there will be no complications. Survivor legal heir will give you noc

Grand father is not legal heir of deceased father and has no share in flat 

2) ypu don’t need his children NOC 

3) for transmission of share in favour of mother you and your sibling can give your NOC 

4) you can execute gift deed for your share in favour of mother 

- As per law , after the death of your father intestate , his property would be devolved upon all the legal heirs equally. , i.e. his wife and children 

- Further, any of the legal heirs can release his respective share in the name of mother after executing a registered relinquishment deed. 

- Out of your fathers legal heirs , none consent is needed for transmission of the share in the name of mother, hence your grandfather is not a legal heirs of your father. 

In the above case muslim law will be applicable as the property belong to muslim

- As per Muslim Law, the right of inheritance of property comes only after the death of a person.

- Further, any child born into a Muslim family does not get his right to property on his birth. 

- Further, distribution of property can be made in two ways, firstly per capita or per strip distribution.

- Per – Capita distribution method is used in the Sunni law, and according to this method, the estate left over by the ancestors gets equally distributed among the heirs. Therefore, the share of each person depends on the number of heirs. 

- Per strip distribution method is used in the Shia law, and according to this method, the property gets distributed among the heirs according to the strip they belong to, and hence the quantum of their inheritance also depends upon the branch and the number of persons that belong to the branch. 

- Further, there is no distinction between the right of men and women; each has right over the said property. 

- However, a female will get half of the male share. 

- Further, out of 100% share, share of mother will be 12.5%. and the remaining 87.5% will be distributed between sons and daughters. .

- Hence, after the demise of your father his property would be devolved upon your mother and all legal heirs but the share of mother will be 12.5 only and remaining will be distributed to sons and daughters , and no permission is needed from grandfathers other legal heirs. 

You need NOC of legal heirs of deceased grandfather for transmission of shares 

for immovable property legal  heirs can execute relinquishment deed to relinquish their share in property 

If the DP is accepting the NOC given by the surviving legal heirs of your deceased father to transfer the shares to your mother's name, then you can very well execute the same.

As a matter of fact your grandfather  (if you are Hindu by religion) was never a legal heir to your deceased father as per the Hindu succession act, therefore his death may not make any difference for the other legal heirs to execute the NOC as desired in favor of your mother.

As per you one more legal heir is also reported to have died, but if that particular legal heir was survived by any other legal heirs, then it would become pertinent to obtain NOC from them too.

Muslim law recognizes two types of heirs, Sharers and Residuaries. Sharers are the ones who are entitled to a certain share in the deceased’s property and Residuaries would take up the share in the property that is left over after the sharers have taken their part.

The Sharers are 12 in number and are as follows: (1) Husband, (2) Wife, (3) Daughter, (4) Daughter of a son (or son's son or son's son and so on), (5) Father, (6) Paternal Grandfather, (7) Mother, (8) Grandmother on the male line, (9) Full sister (10) Consanguine sister (11) Uterine sister, and (12) Uterine brother.

In Non-testamentary succession, the Muslim Personal Law (Shariat) Application Act, 1937 gets applied.

Now since the father of your deceased father has also died, there is no question of his successors from outside the family.

You can submit a letter to the DP stating that so and so legal heirs are died without leaving any survivors behind and to accept the NOC that you have executed in favor of your mother, let them give a reply  for which you can take legal accordingly.

Dear Client,

 Since, in this case there is no information related to nominee, so considering there is no nominee with respect to the shareholding in DEMAT form.So, the following are the requirements for the transmission of the share certificates:

1. If value of shares upto Rs. 500,000 - any two of the following documents required are:

1. Notarized copy of the death certificate
2. Transmission Request Form(TRF)
3. Affidavit – to the effect of the claim of legal ownership to the shares,
4. Deed of indemnity – Indemnifying the depository and Depository Participants  (DP)
5. NOC from legal heir(s), if applicable or family settlement deed duly executed by all legal heirs of the deceased beneficial owner.

2.If value of shares more than Rs. 500,000 or more- any two among the above mentioned documents and additionally,surety form, succession certificate or probated might be required.

Thanks and Regards

1. You shall have to first apply for and avail the succession certificate of the share of your deceased grand father.

2. Thereafter the questioon of NOC will arise.

3.The Companies will not allow there shares to be transferred without the Court order.

1. First of all the Court  shall have to issue Succession Certificate ascertaining the successors of the moveable properties of your deceased grand father.

2. There afier you can collect NOCs from them and apply for the transfer of there shares in your name.