If you sell unlisted shares within 24 months, the gains are treated as Short-Term Capital Gains (STCG) and taxed as per your income tax slab. If held for 24 months or more, they qualify as Long-Term Capital Gains (LTCG) and are taxed at 12.5% (without indexation). STT is not applicable on unlisted share transactions. If the shares are sold after listing on a stock exchange, the tax treatment follows the applicable rules for listed shares.