time limit for review of Orders under Section 107(2) of the CGST Act, 2017.

As per the Section 107(2), the time limit for review any order, passed by the Adjudicating Authority, is 'six month from the date of communication'. What is the meaning of 'communication'. Is it the date of receipt of the Order by the Commissionerate, or the date of Order or the date of dispatch of the order. Is there any clarification issued by the Board or Court? What is the normal practice?