If you have the physical  possession of the property vie a registered sale deed executed by court in your favor, then the NBFC cannot do anything about it except to catch hold of the borrower because, they have not impleaded themselves as a party to the suit neither they have taken any steps when you filed the execution petition too.

You can file a suit for permanent injunction against the bank to restrain them from interfering in you possession and enjoyment of the property that you acquired through a registered sale deed.  

Your right is secured through court. Here the case needs to file filed against X for cheating and fraud. 

An unregistered agreement to sell, executed before the seller mortgages the land, will not invalidate the subsequent mortgage in favor of the bank.

2)The mortgage, being a registered document, takes precedence over the unregistered agreement

3) sale deed is subsequent development 

The issue in your case is un registered agreement for sale was executed prior in time .had registered agreement for sale been executed you would have a good case 

2) mortgage is registered document and would prevail over the un registered agreement for sale 

3) it is the seller who has cheated you and failed  to disclose that property was already mortgaged when court passed orders for execution of sale deed 

4) you can raise it as defence but your chances of success are bleak 

If a borrower defaults on their loan, the NBFC can initiate SARFAESI proceedings, which can include taking possession of the secured asset and selling it through auction. 

A registered sale deed normally signifies that the property has been transferred to a new owner. However, if the NBFC holds a valid security interest on the property and the borrower has defaulted, the NBFC's claim takes precedence. 

However, in your case, it was not the owner who had executed the registered sale deed in your favor but it was by an order of court.

Moreover, since the property was mortgaged but the NBFC has registered only the memorandum of title deeds alone, you may not find a reflection of this transaction in the encumbrance certificate.

In all the probabilities, you were not in the knowledge of the so called mortgage loan even at the time of getting the property registered to your name through a court order. 

The suppression of the fact of the registration of property to your name by the owner to the NBFC  and suppression of the fact of the property being mortgaged to NBFC  after entering into an agreement with you, is a criminal offence and both you as well as the NBFC can initiate criminal actions also against him, but for now you have to defend your interest by stating that the property was already transferred to your name by a registered sale deed through court especially even before the NBFC had declared the account as NPS and before invoking the sarfaesi act , hence you may take shelter on this point and defend your interest properly in the court proceedings. 

Dear Sir/Madam,

In the facts and circumstances mentioned by you, your property is safe to the much extent. But, you are suggested not to sit idle, rather submit the police complaint alleging the seller/ Mr X for committing fraud with you and the bank and without informing you mortgaing the said property. It is quite possible that police will collect the requisite information regarding other assets/property of Mr X and the NBFC may recover the amount through that property leaving your property untouched.  

As you have courts order you can seek execution if the same and take possession 

if you need any detailed consultation you can contact me through kaanoon