Mortgaged the property

Dear Sir/Madam, A is mortgaged the property to B on the condition to return the amount with in 5 years in the year 1955. But A is not paid the amount within time to B. B also not recovered the amount by filed foreclosure suit against A. The said property is in the name of B and continued in his legal heirs name till date. Now C is buyer. My question is that, 1. what is legal status of A over the property, he has to be file for redemption suit against B?. 2. what is the legal status of B over the property, B has not filed foreclosure suit till date and transferred the rights pavathi khatha in his legal heirs and they are sell the property to C. 3. What is the legal status over the property of C. please describe.