Krishnendu Das,
Hope you have already refered SAP note 1873593 - LO-BM : Batch management flag is not possible to set / unset.
From above note
Within SAP standard there is no other way to change the flag. There are reports to do this, but this reports are not free of charge and not handled in SAP Support.
See notes 533276 and 533383 (Reports RVBCONVMAT2BM and RVBREVMATBM)
If you are interested in using this reports or need more information about this reports please don’t open a customer message! The SAP Support cannot give you details about this reports, only consulting can do this.
To contact the consulting team, please proceed as described in the notes and send an e-Mail to BMtools@sap.com.
BR
KK