Non Taxable Supply vs Non GST Supply - Goods and Services Tax - GST

Dear Experts, The definition of exempt supply u/s 2(47) of CGST Act includes Non Taxable Supply. Does the term non taxable supply is equivalent to Non-GST supply as per table 3.1.e of Form GSTR-3B Table -8 of GSTR-1 ? If yes. Whether ITC reversal u/r 42 needs to be computed on total of (exempt supply + non gst supply )? We are showing reimbursement amount in Invoice as Non GST supply in GSTR-1 3B . whether reversal u/r 42 is required on non gst supply?