Companies (Cost Accounting records) Rules 2011 was issued by MCa on 3rd June 2011 making it mandatory for accounting periods ending on or after that date.
So under normal cases, the said records are mandatorily to be maintained for FY ended 31032012 and a Compliance Report has to be certified by a practising CWA and uploaded to MCA within 180 days , recently extended by another 3 months.
The notification mandates -- Companies having turnover exceeding 20 Cr or Net worth 5 crore during the immediately preceding FY shall be covered by the notification.
Here immediately preceding FY means FY ended 31032011 or 31032012.
Regards,