REVERSAL OF TRAN CENVAT CREDIT - Goods and Services Tax - GST

Dear experts 1] Whether the taxpayer engaged in the supply of works contract services need to reverse un-availed CENVAT credit landed in the ITC ledger as provided under Section 140 , in the event of obtaining the Occupancy Certificate or Completion Certificate under Section 5[b] of Second Schedule to the CGST Act ? 2] Whether such CENVAT credit under Section 140 automatically takes the legal form of ' Input Tax' as prescribed under Section 2[62] in the absence of any inward supply of services or goods or both under the CGST Act , irrespective of requirement of reversal of ITC under Section 17[3] ? Plz pour thoughts.