The profit gained from the sale of gold is taxable under the 'Captial Gains' for individuals and in case of gold and jewellery dealers, it is taxable under 'Profits and gains of business or profession'.
The amount of tax liability and exemptions from payment of tax available will depends on how long you hold it.

* If you buy gold or gold jewellery and sell within 36 months, it is treated as a short-term capital asset.

* In case, you buy gold or gold jewellery and sell after 36 months i.e. three years, it becomes a long-term capital asset.

The gold sold can either be purchased by you or gifted to you or acquired by inheritance. The computation process will depend on the mode of such acquisition and the holding period.

The short-term capital gains are added to your regular income and are taxed at the slab rate applicable to you whereas long-term capital gains are taxed at 20 per cent and applicable surcharge and education cess.

Gold gifts up to Rs 50,000 in aggregate in a year are fully exempt. In case, you received gold as a gift, would become taxable at the time or receipt in case value of all the gifts received by you during the year exceeds Rs 50,000 in a year.

The capital gain tax liability is triggered only at the time of sale of gold which is received as an inheritance or gift. In 2017, the government shifted the base year for calculation of the indexation benefit from 1981 to 2001.
In case, you don't' make a profit on selling your gold, it is treated as a capital loss and you can mention the same while filing your ITR returns.