Section 44ADA says if you are earning from any profession of accountant, doctor etc and if your total receipt is upto Rs 50 lakh then you can show it's 50% as your income from that profession and you don't need to maintain books of accounts.
If you have only done investment then no capital gain tax is to be paid capital gain tax needs to be paid if you sell your investment and it will be calculated as sale consideration less indexed cost of acquisition.
If you are doing Forex trading it will be business income and not professional income and if it's non speculative i.e. it is not intra day then you can declare it's income at 8% of turnover or at actual profit whichever is higher.
It's not always necessary that if TDS has been deducted under section 194J then it's professional income so you must be able to prove that TDS deducted is actually your consultancy income and the limit has been discussed by myself above.
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