Sudden crediting of money in the bank

Well, as my friend is from a small town where women don't really go to banks so his mother had a part of his father's salary every month and she saved it at home. 2 years back they got transferred in Mumbai and because they were going to need that money so she put that in her new account in Mumbai (but without pan card because there wasn't any big transactions and all). So now because she had to make a D.D for his admission she gave her pan card details and all that. Details of credit:- Around 1.3 Lakhs cash from her( when she came to mumbai) 1.5 Lakhs from insurance policy(just now) 80 thousand from F.D (just now) and last 25 thousand cash from her ( just now) So will there be any problem regarding tax ? Can they come and ask that why didn't you showed all that money etc? And how to overcome that, as all the money is white money as his father is a simple government officer with all his tax details and all this money with his mother is her savings from years as in his old town women don't go to banks, they don't know procedures and all? I really want to help him. Can you please help Thank You