Capital Gain on sale of shares holding

As rightly mentioned in your query, the gains arising from sale of shares will be taxable in the hands of the shareholder(s) and not in the hands of company whose shares are sold.

I believe, you are looking at taxation from the perspective of seller (i.e. shareholder). In this regard, please note that if the company (whose shares are sold) is a listed entity and the gain is less than INR 1L and is held for more than a year, you can claim exemption. If not, then the gain will be taxed as long term capital gains. You can consider claiming indexation benefit. For computing capital gains, you need to apply following formula:

Sales Consideration

(-) Cost of acquisition (if held for more than 1 year / 2 year, indexed cost of acquisition)

Capital Gain / (Loss)

The formula is already mentioned in my earlier reply