Which calculation is correct in gst

Base Rate    = 100  , GST % 12  ( S-6,C-6) , Rate is Inclusive of Tax (MRP)

Case 1

       Taxable =  100 * 12 / 112

       Taxable = 89.29

       SGST   = 89.29 * 6/100     =   5.36   

       GST  = (SGST+ CGST)     5.36+5.36  =  10.72

Case 2

     SGST Calculation

       Taxable =  100 * 6 / 106

       Taxable = 94.34

       SGST =  94.34 * 6 /100       =  5.66

       GST   = (SGST+CGST)   5.66 + 5.66   = 11.32