You should do 2 things;

File Returns:
You should already know your income and the tax deducted every year. You can long into the income tax website and see your tax credits [Form 26AS], just to make sure your employer has credited the tax to Govt. Calculate your tax, deduction and file the returns.

File a complaint:
An employer has to provide a TRACES generated Form 16 to the employee by 31-may. Failure to do so attracts penalty. You can provide a written complaint to the local IT ward office giving out the details

You should do 2 things;

File Returns:
You should already know your income and the tax deducted every year. You can long into the income tax website and see your tax credits [Form 26AS], just to make sure your employer has credited the tax to Govt. Calculate your tax, deduction and file the returns.

File a complaint:
An employer has to provide a TRACES generated Form 16 to the employee by 31-may. Failure to do so attracts penalty. You can provide a written complaint to the local IT ward office giving out the details. Edit For more info see Section 4.6