2)Suppose I don't have an income but I made intraday profit of above ₹2. 5 lakh,do i have to pay tax? If yes,then how much?

General
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Everything you need to know about Markets and Taxation is here -

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Read it but couldn’t find specific answers.Please solve my issue here.

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DDK - Did you read the entire module? If no, please do so. This is probably the best content related to Markets & Taxation and you will find your answers.