Refund of advance against property deal.

My wife and daughter entered to an agreement on Rs. 100 stamp paper with a lady duly notarized for purchase of house with time limit of 45 days. With in 45 days my daughter's husband asked the brother of the lady for registry of house giving 3 days time. the entire deal is handling by the brother of lady only. The brother of lady refused to present on the day of registry. after that my wife got seriously sick with gall bladder cancer and she was admitted in hospital for operation. during her stay in hospital only we again approached to the brother of lady and get extended the validity of the agreement for further 1 months as well as added the name of my daughter's husband also in purchaser names. My daughter has applied for a loan through a bank. Earlier loan was approved against the application by husband of my daughter by his employer firm but during hospitalization of my wife due to company's internal problems company has refused the loan. Now if my daughter is not getting the loan within the time limit or her loan is not sanctioned/approved and lady refuses for registry of house, can my wife get the refund of Rs. 5 lacs which she had paid to lady as an advance at the time of initial agreement. There is one clause in agreement which says if loan is not approved or sanction, seller will refund the advance amount