Hello Sir. Answers to your queries are as under:
Answer to Query 1- Buyback:
If a company buys back its shares, the company itself has to pay tax on it under section 115QA of the Income Tax Act, 1961 and consequently, the consideration received by the shareholder is exempt from tax under section 10(34A) of the Act.
Accordingly, there will be no tax liability in your hands on consideration received on buyback.
Answer to Query 2 - Direct sale to another institutional investor:
An equity share of an unlisted company shall be considered to be a "long term capital asset" if it is held for a period of more than 24 months. In the present case, since it is more than 24 months from the date of your original investments, the shares would be considered as long term capital assets and the resulting capital gains would be "long term capital gain".
Further, there is no effect of dilution on the period of holding of the asset.
In such case, assuming that you are a non-resident for the purpose of Income Tax Act, you would be liable to pay tax at the rate of 10% (plus surcharge and cess, as applicable) under section 112(1)(c) of the Act (indexation and forex fluctuation benefit would not be available).
Hope to have resolved your queries.
Best regards,
CA Yogesh Malpani