You have posted that:
“The debtor who was occupying this property at that time when he took money from the bank has not mortgaged this property and later sold it so how could Bank claim its right on the property.”
This implies that the debt was not secured and the property in question was not given as security.
However as posted by you ,the bank has procured attachment order for the property to recover its debt.
The bank did not seem to be sleeping but pursuing a safe recourse and now may be amused at its success.
Your lawyer after examining all docs on record may opine that debt is time barred.
Since notice has been pasted on the property owned by you now do you have any other option than to contest it?
Approach a lawyer well versed with such matter and handling DRT cases AS AP with all docs on record and proceed under expert advice of your lawyer.
Alongwith other/previous owner attempt and find out the whereabouts of the judgement debtor and his assets.
YOur lawyer shall appraise you on how to pull him to court and police................