Form 16 : Your employer will give you this form. It has information about the income earned and the tax deducted from your salary during the year.
Form 16A : This form is also called a TDS certificate and is for tax deducted at source on other income such as interest on bank deposit. It is given to you by financial institutions such as banks or companies, which deduct tax at source every month or year.
Summary of all bank accounts or passbooks: You need a summary of all bank transactions carried out during the financial year, which include income earned, investments made, expenses etc.
Property details : If you have purchased or sold any property during the year, you will need the details. If the property bought is on loans, do keep a copy of the home loan details with you. If you sold your property then you may be eligible for capital gain tax.
Interest certificate : You need this certificate if you have taken a loan from a bank or financial institution, to buy a house.
Broker contract notes : Bills for sale and purchase of shares and dividends.
Investment details that have not been disclosed in form 16. For example if you have invested in tax-saving tools such as life insurance, Public Provident Fund and it is not mentioned in form 16 issued by your employer, you need the proof of investment.
Tax payment challan, if any: If you have paid advance tax, you need to attach the proof.