Source of funds in IT returns

To briefly encapsulate the solution, capital withdrawals or loans from a firm do not appear in the income computation of an ITR but should be tracked in a personal balance sheet, whereas any distributed share of profit must be declared under Schedule EI. Ensuring that the firm's ledgers exactly match the partner's bank statements is the primary mechanism for explaining the source of these funds to the tax authorities.

To prevent any notice in future for source of funds how to inform them in returns

There is no separate field in the ITR to state the source of a bank deposit, so the return itself does not need to explain it. Your records do. If the amount is a withdrawal from your capital account or a loan from the firm, it is not income and stays out of the income computation. Your share of the firm profit is exempt under section 10(2A) (Schedule EI), while remuneration and interest from the firm are taxable business income. Keep the firm ledger, your capital account statement, the partnership deed and the bank statement so the transfer ties to your account in the firm books. If a notice comes, reply with those documents. This is general information based on the facts given.