Dear Mr. Nirav,
In case of stock transfer / consignment against form-F in B-Mumbai, A-Ahd. will not be liable to charge and VAT or CST subject to submission of Form-F & other evidences obtain form B-Mumbai. In such transaction 2% CST [Against Form-C] is benifited.
But, before entring such transaction pl. note that, as per the provisions of Sec. 11(3)(b) of G.VAT Act, 2003, 4% of goods used as Raw Materials in such stock transferred or consigned goods are required to be reduce when you claim Input Tax Credit on RM or Finished Goods.
Therefore, before entring in such transaction, you should calculate the benifit looking to your business transaction method.