The documents you have prove that the property belongs to you but other than the documents you have, you ought to have other documents in order to be a part of the society where other flat owners are living and you can sell the property if you want and be sure that all rules have been complied with by the builder.

Therefore obtain these documents too. 

No. But it's better you seek explanation from him seeking all those documents vide letter or notice

Yes you can but you need to get those documents if available with builder

Registered sale deed confers clear and marketable title to property 

2) you need copy of OC , possession letter from builder 

3) you can sell your flat but buyer will ask for OC 

1.  It will not cause any problem to determine your ownership to the flat, as these are secondary documents.

2.   Your ownership is determined by the registered sale deed in your favour, which is the primary document, to prove your ownership title to the flat.

3.   Contact the builder/developer at once through your confidant person in India, as you are outside India, and try to procure the completion certificate, occupancy certificate, Allotment letter, possession letter, etc.

4.   You can sell the flat to a prospective buyer, since you possess a registered Sale Deed for the flat in your favour. You can get the Patta/Khata for the property from the jurisdictional Corporation/Municipality, after paying the admissible taxes by mutating your name as owner in the revenue records.

Completion certificate and occupancy certificate being issued  by Municipal Authority, same can be obtained from GHMC. Apart from sale deed other document  are secondary without much legal significance. You will not face any problem in selling the property. You also have tax receipts.

Dear Client, 

In order to further sell your property, the documents you need are - Letter of allotment, Sale deed, sanctioned plan, society documents, encumbrance certificate, and sale deed.

Thank You

As you acquired the property many years ago, the documents not in your possession are not absolutely necessary for you to sell it. While the registered sale deed legally confers title and ownership on you, besides possession and enjoyment of the property, the tax receipts are documents evidencing your title. 

1. The documents what you have mentioned are essential documents that is to be handed over to the buyer by the builder/seller at the time handing over possession after registration of the property.

2. The buyer may not be able to sell the property at a later stage without the essential documents inducing transferring khata and electricity connection and water supply  to his name

1) If you're living or your family is living in the flat there is no issue for ownership in general.

2) If when you try or willing perform to sell property you require all the documents list which you have mentioned in the question.

1. In the lack of these documents , you will not face any problem for ownership , but at the time of selling the flat you can face trouble 

2. Yes, and also at the time of taking home loan by you and the intending buyer 

- You can approach the said builder for getting the same as you have your legal right to get these documents , and if refused then issue a legal notice to him. 

You can sell the flat 

Society must be having copy of OC on its records 

obtain copy of OC from the society and then sell your flat 

1.  You can obtain copies of the completion certificate and occupancy certificate from flat owners' association, which will be in existence in your apartment complex.

2. Moreover  the Builder would have handed over all the original documents of the entire property to the authorised personnel representing the Association. Please contact the President and other office bearers of the Association, who may be of some help to you, in procuring some documents in respect to your flat.

3.  Since you have the original sale deed executed by the builder/owner in your favour, there can't be any problem for you to sell the property after obtaining Patta/Khata in your name from the jurisdictional Corporation/Municipal Office after payment of the admissible taxes.

The prospective buyer will act on the advice of his lawyer who may opine that the missing documents are essential without which the title can be defective hence he may not recommend purchase. 

Besides the bank panel lawyer also would insist on production of the missing documents without which he may not recommend grant of home loan to the buyer. 

First, find a prospective buyer. Let him/her check the documents through their lawyer. If they raise the issue of the missing documents, convince them why you cannot produce them now. Also, show them the favourable opinions rendered on this forum. There is absolutely no impediment, in my view, in your passing on a good title to your buyer.

Dear Client,

You will have to get an endorsement from the concerned authority about the housing society and mentioned required certified copies of the allotment letter, society documents etc.

Thank You

- You can arrange these documents from the society.

- As per rule , the society must having these documents at the time of its formation. 

you can sale the flat as you have a valid sale deed and possession of many years and even tax receipts are on your name which proves your ownership. 

Then be silent and assume the said transaction genuine and move forward