Answer for Who is liable to file Income Tax Return and what is the due date

Whose Liability??
Every Individual, Hindu Undivided Family and Company whose net wealth exceeds the maximum amount which is not chargeable to wealth tax in any previous year ending of 31st March is liable to file the wealth tax return. The maximum limit of net wealth not chargeable to tax under the provisions of the Wealth tax Act, 1957 is Rs. 30 lakhs at present.
Net wealth is the aggregate value, computed under the provisions of the W.T. Act, 1957, of all assets (including deemed assets), belonging to the assessee on the valuation date, MINUS the aggregate value of all debts owed by the assessee on the valuation date which have been taken in relation to the assets attracting wealth tax.
Due Date!!
The due date for filing the wealth tax return is the same as the due date for filing the I-T return. For individuals and HUFs, the due date is July 31following the financial year for which this return is to be filed and, for companies, it is September 30 or November 30 (as the case may be)