Property seized with bank

My Dad had property against which he took loan (I am not sure when he took loan). I just know loan is taken from HDFC bank. He had around 6 lakhs pending from past few years. Interest against loan also amounts to now 6 lakhs so total around 12 lakhs is pending. Finally property was seized by bank but my dad took stay order from court to stop auction and court passed order to repay loan. My dad is no more now. I don't have any details. Why he did not pay 6 lakhs amount for so long as property rate is much higher. I suspect there is some income tax case against my dad and there was chance that income tax dept would have seized property if my dad would have cleared loan. I don't have any details regarding case. Also, important documents got seized along with property. My questions 1) is there possibility to reopen seize property so that atleast we get important documents back. 2) how do I get details about case which was against my father (if there is any?) 3) should I approach bank to discuss anything about property or should I follow more formal legal approach?