Dissolution of firm and capital gain

If a firm has shares of an unlisted company and acquisition price is say Rs. 10 Lacs . On dissolution the partners devide shares of Rs. 5 Lacs each being 50% sharing ratio.

If the Book value of such shares as on the date of such dissolution is say 40 Lacs. Whether Capital Gain Tax is applicable on the firm on the date of dissolution or it will be applicable when the partners sale such shares.