As per the CBDT New Notification the Part A of Form 16 Mandatory to Download from TRACES portal only & Part B must be prepare by the Employer.
The new Form16 notified recently by Income Tax Department (Notification No. 11/2013 dated 19/02/2013) is applicable for FY 2012-13. The new Form16 contain two parts, Part A and Part B (Annexure). Part A contains details of Tax Deduction and Challan deposit details whereas Part B contains the Income details.
Further, it is made mandatory to all Deductors (including Government Deductors who deposit TDS in Central Government Account through book entry) that, the Part A of Form 16 shall be generated only by downloading it through TRACES Portal (https://www.tdscpc.gov.in), for all the deductions done on or after 01/04/2012 under section 192 (Salary Income), and issued duly authenticating it either manually or with digital signature.
Part B of Form16, shall be prepared by Deductor manually and issued along with Part A duly verified and authenticated in accordance with Part A details.
Refer CIRCULAR NO. 04/2013 dated 17th April 2013 stating the above.