I am a retired govt employee and do share trading. How income tax is calculated?

[Felaket]

I am a retired govt employee and do share trading. How income tax is calculated? The CBDT has issued a circular in February 2016 stating that whether the income from listed share should be treated as business income or capital gains, the first choice is with the tax payer and the assessing officer is bound to accept the choice so made. Such choice can only be made in case the shares are held for more than 12 months