Right to information

It is you or your sister to find out her property.

No legal issue is involved in your query for consideration and obligation by experts.

There are separate verification agents/private detectives exclusively specialized in the profession and commercial banks use their services to find out the assets of those default borrowers where there is no security appears to Bankers and to get information from them and then attach that asset for executing/attachment/ recovery process.  Engage a professional or contact deceased relatives who may be friendly with him and your sister.  If he is a Government employee, wife can seek such information from the employer as he might have submitted Bank account particulars, asset statement or availed some housing loan, contributed to insurance etc., (All this if there is no legal separation)

Try with employer and file such RTI Application to ITO .  Several alternates were suggested.

Your sister's husband salary will be credited to Bank. you can find out the bank details from the dept. Once you find out the details it will be not difficult to find out the other property details.

The posting suggests no legal issues. Please verify with the office whether he had filed the property returns.

There is no legal issue involved. 

Thew deceased being govt servant was under intimation to intimate property transaction to the deptt.  Such details can be had under RTI.  However, in case he had been violating this condition then no information will be available with deptt.