Attachment before judgement.

Contact a local advocate as it is absolutely not possible to attach an asset already mortgaged to the bank.  The advocate may issue suitable notice to the lender asking him to present the documents in possession.

The lender ought to issue notice and file a recovery suit by paying the court fee as per market rate as he was not in possession and such procedure takes long time to recover.

If you wanted to dispose of the property, you have to establish yourself as the only legal heir and have absolute rights on the property, and then only you can dispose of the property.

Also, find out from the Bank where the Home loan account is covered under Group insurance as you need not pay the amount and the institution claims insurance and returns back the documents of the title deed to the Nominee.