The limitation what you refer here pertains to adverse possession only and not for the clear and proper titled property. 

The unregistered relinquishment deed is invalid in the eyes of law. 

If the shareholders raise a dispute in this regard and claim their entitled share stating that the unregistered deed is invalid,  then the court may decide in their favor. 

Hence you may look for an alternative 

Registered relinquishment deed was necessary 

mere notarised relinquishment deed is not suffice t 

however conveyance deed executed in 1998 and no legal heir has taken legal proceedings to set aside sale deed 

the claim would be barred by limitation 

Buying a property in Delhi can be a complex and risky process, especially when it involves inherited properties and unregistered deeds.

First of all, let me explain what a notarized relinquishment deed and a conveyance deed are, and how they differ from each other. A notarized relinquishment deed is a document in which one or more legal heirs of an inherited property give up or release their rights in the property in favour of another legal heir or co-owner. A notarized relinquishment deed is not registered with the sub-registrar’s office and does not have any stamp duty or registration fee. A conveyance deed, on the other hand, is a document in which the owner of a property transfers the title, ownership and rights in the property to another person, usually for a monetary consideration. A conveyance deed is registered with the sub-registrar’s office and has stamp duty and registration fee as per the state law.

A notarized relinquishment deed is not valid for transferring rights in immovable property in India. Only a registered deed can legally do so. Hence, a notarized relinquishment deed is non-existent in law and has no effect on the ownership of the property. A conveyance deed, however, is valid and binding for transferring rights in immovable property in India. A conveyance deed is also necessary for obtaining mutation of property, which is the process of changing the name of the owner in the revenue records of the government.

Based on this, it seems that the previous owner of the property you are planning to buy had obtained a valid conveyance deed from DDA in 1998 based on a notarized relinquishment deed from eight legal heirs of his father. However, since the notarized relinquishment deed was not registered and had no legal effect, it is possible that some or all of those legal heirs may challenge the conveyance deed and claim their rights in the property at any time. This may create a dispute over the title and ownership of the property and affect your rights as a buyer.

Therefore, as a cautious buyer, you should not go ahead with the purchase without verifying the authenticity and validity of the notarized relinquishment deed and the conveyance deed. You should also check if there are any other legal heirs who have not given up their rights in the property or if there are any pending cases or disputes over the property. You should also obtain a mutation letter from DDA to confirm that the name of the present owner is recorded in their records as the owner of the property. You should also ensure that all other documents required for mutation of property are in order, such as copy of sale deed, indemnity bond, affidavit, receipt of up-to-date property tax payment, etc.

If you buy the property without verifying these documents and issues, you may face problems when you sell the property in future or if any legal heir challenges your ownership. You may also have to pay additional stamp duty and registration fee if you have to execute a fresh conveyance deed or rectify any defects in the existing one. You may also have to face legal hassles and expenses if you have to defend your title and ownership in court.

Therefore, my suggestion is that you should consult with a lawyer who specializes in property law and get his or her opinion on whether it is safe and advisable to buy this property or not. You should also do your own due diligence and research on the history and status of the property before making any decision. I hope this information helps you understand some of the legal aspects of your situation.

This relinquishment deed executed by the legal heirs of the previous owner, ought to have been registered.

Since it is not, the 7 legal heirs themselves, or their kin, can create trouble any time they want. Thus, since everything does not looks good, you should take opinion from a local lawyer and ask him to conduct a TSR and furnish a report you. Based on the local lawyer' opinion, take a call of whether or not to go ahead with the deal. 

- As per law, after the demise of owner of the property intestate, his property would be devolved upon all his legal heirs equally. 

- Further, any of the legal heir can release his share in the name of another one after executing a registered relinquishment deed. 

-  As per the Section 17(1)(B) of the Registration Act, 1908, the registration of  the relinquishment deed is mandatory.

- Further, an unregistered relinquishment deed is not admissible as evidence in court.

- Hence, the legal heirs can claim his share in the property , as the said deed is not valid. 

- You can face trouble at the time of selling the property . 

Since there is a registered conveyance deed in favour of origional owner and as you too is purchasing through registered sale deed hence as such no issue seem to arise in future. As utter precaution you can take affidavit in confirmation. 

Dear Client
Relinquishment Deed: A notarized relinquishment deed, even if not registered, can still hold some legal value. However, a registered relinquishment deed is generally considered more secure and legally binding. It's advisable to try to get the relinquishment deed registered if possible. This can help avoid disputes in the future.

Conveyance Deed: The conveyance deed executed and registered by DDA in 1998 is a crucial document that establishes the transfer of ownership from the previous owner to the present owner. Ensure that you have a clear and legally valid copy of this deed.

Mutation Letter: The mutation letter is essential for updating the property records with the municipal authority to reflect the current ownership. It is an administrative process, but it's important to ensure that it accurately reflects your ownership.

Challenge by Legal Heirs: In India, legal heirs do have the right to challenge property transactions, especially if they believe that their rightful share was not duly considered. However, the 1998 conveyance deed and mutation should provide strong legal proof of ownership. Generally, the limitation period for challenging such transactions is 12 years from the date of knowledge, but it can vary based on specific circumstances and legal interpretations.

Cautious Approach: To minimize future risks, it's advisable to consult a local property lawyer who can conduct a thorough due diligence check on the property's title and advise you on any potential issues. They can also guide you on whether additional steps, such as obtaining a registered relinquishment deed, are necessary for added security.

Selling the Property: When you plan to sell the property in the future, having all the necessary legal documents in order, including the 1998 conveyance deed and mutation records, should help facilitate a smooth sale. However, it's always wise to consult with a lawyer during the selling process to ensure compliance with all legal requirements

He can’t challenge it after limitation even if challenged the same will not succeed 

A notarised deed of relinquishment alone is not legally sufficient. The relinquishment deed needs to be registered. Otherwise, it is not valid in law. If there is proper evidence, the conveyance deed can be challenged. That risk always exists.

non registered relinquishment deed not valid. 
Risky deal. 

Indemnity bond is not sufficient 

2) since title is not clear and marketable you can cancel the deal and seek refund 

3) legal heirs should execute registered relinquishment deed to confer clear and marketable title to property 

Yea you can explore that remedy 

It is not understood that on what basis you have been advised for re-allotment by DDA .

Where is the question of re-allotment because the original allottee is not alive and his legal heir has already sold the property by a registered sale deed in favor of a buyer and that buyer is now selling this property to you.

So how can DDA re-allot the property in your favor or in favor of your vendor?

Don't fall prey to such non maintainable advises.

The problem here is that the legal heirs have executed an unregistered relinquishment deed, hence the title to the seller is defective. 

Your vendor did not bother about the legality of the issue while he purchased the property hence his title is also defective due to the said reason.

Now it is seen that it will not be possible for your vendor to gather all the legal heirs and get a ratification deed relinquishing their rights by a registered document.

Hence it is advisable that you keep away from this property, demand the vendor to return the booking amount with interest because he failed to produce the valid and substantial documents pertaining to the property.

Indemnity bond will not hold in the event of any dispute and the bank also will not grant loan on the basis of the indemnity bond

Mere reallotment by the DDA shall not rectify the inherent defect in the title of the property. If limitation and evidence are available, the title can very well be contested.

- Since, free hold was done in 1997 , then there is no possibility of challenge the said Relinquishment deed and a claim by the legal heirs after a long period of 25 years. 

- Hence, if that seller is ready to execute Indemnity bound then you can proceed to purchase the property. 

- However, it is suggested that if the legal heirs are alive , then they can be a witness in the registered sale deed.