You can get it from builder. But if. You have allotment letter possession certificate is not necessary

The issuing authority the Municipal Office will have a copy in their file, you can obtain a certified copy of  same from them. Anyway it is 27 years back, the PC has become useless now but you can still have it if you pursue it properly.

Approach builder for copy of possession letter 

In any case you have registered sale deed in your favour and are in possession for 27 years.absence of possession letter would not make material difference 

- A possession letter is a document issued by the developer in favor of the buyer stating the date of possession of the property.

- Further, it is issued , when the builder gets a completion certificate from the designated authority, and it is issued once to the buyer from the builder. 

- However, a possession letter does not make the buyer the legal owner of the property. 

- Since, you bought the said property long ago and having title deed including all other documents , then itself it is a proof of occupation and possession of that property. 

- You can issued a possession letter to the intending purchaser after narrating that you are in use and occupation of that property since last 27 years , and now transferring the possession to the buyer at the time of execution of sale deed. 

It can be searched from the record of builder.

It is not possession certificate, may be it would be the occupation certificate or construction completion certificate.

Way back 27 years ago, the OC or CC was not very much essential and the builders used to manage to handover possession with just a possession letter without OC or CC. 

If you are able to locate  the builder now, you can ask him to issue a possession letter with back date or you can inform the buyer that it is not available , if he is not satisfied or not willing to buy the property you may look for some other buyer. 

No need as of now if you have CC certificate and builder has handed over building to society and you have society's certificate as member of the society.

And paid payment to builder as per the sale deed then no need to worry about it if you have the possession of the flat last 27 years.

If you want sort this issue I can prepare sale deed for you according to that and buyer has to accept it.

Dear Client,

                 This procedure explains various ways to Apply for Property Possession Certificate in Gurgaon.
To obtain a Property Possession Certificatein Gurgaon the applicant has to approach Revenue Department.The applicant should get the application form from the Revenue Department Authorities.Fill the application with the Required details.Now attach the required documents mentioned and submit the application to the concerned Officer in the department.Once the documents are submitted you will be provided with an acknowledgement, please keep it safe for future reference.It may take 7 days to process the application form.After processing your request, field verification will be done by the RDO or tahsildar or respective authorities.They notify you through e-mail or by SMS to collect the Property Possession Certificate when it’s ready.They will ask you to sign in a register for the collection of Property Possession Certificate.

Thanks & Regards

I presume your buyer needs the occupancy certificate, and not the possession certificate. The original promoters have to obtain the occupancy certificate from the local body, the municipality or the municipal corporation, as the case may be. As 27 years have elapsed since you purchased the property, there is no need to insist on the occupancy certificate now. If the prospective buyer still insists, you have to get it from the original promoters.

1. Have you got your sale deed registered?

2. If yes, then you are it's  title holder.

3. Who is in possession of the property?

4. You can inform the buyer that the allotment letter is not traceable and sell the property with the help of the registered title deed.