Form 16 not given

Considering your income to be 350,000/- and investments made upto 100,000/-, you are still liable to pay some tax. Check your 26S, if any TDS has been deducted by your employer. If your employer has not deducted any TDS, then they shall not furnish form 16. Does your employer give you salary slip every month? What is the break-up of the CTC? If they have not deducted TDS, then you shall be liable to pay self-assessment tax.

For filing IT returns for the FY 2012-13, the last date for filing was on 5th August. If you have not filed your returns then do it at once. If there is some tax liability, then pay self-assessment tax, and thereafter file your IT returns.