Service tax payment under reverse charge

Yes, it is correct

CENVAT in case of Reverse charge can be claimed in the month of the payment of service tax to the department.

e.g. service tax has been paid to govt(under reverse charge) on 4th of Oct'12

Then, the same can be utilised for the payment of Liability(under normal provisions) for the m/o Oct'12

Credit based on payment.

Therefore for the month of January 13 we can pay on or before 31st and if so done would be available for payment of ST for month of January which is payable on 5/6th Jan.