Sale of stock in hand on which GST enhanced w e f 1st Oct, 21

There has been enhancement of GST rate on Carbonated Beverages of Fruit Drink or Carbonated Beverages with Fruit Juice. ( Heading 2202) • GST Rate enhanced from 12 % (total 12% ) to 28 PLUS 12% CESS  ( total 40% )WITH EFFECT FROM 1ST OCT. 21

My query which I would be happy to get solved is what position will be of

Such stock in hand as on 30^th sep 21 that was purchased by us prior to 30th Sep 21

And is lying un sold as on 1^st of October, 21.

Will such unsold stock in hand prior to enhancement can be sold at previous rate (12%) or at  new regime (40%) will be applicable