Adjustments in Trading Account:
- The goods sent on sale or return for Rs.600 should be adjusted in the trading account. Since the goods were initially recorded as actual sales, they would have been credited to the sales account. To correct this, the sales account should be debited and the returns inward account should be credited with Rs.600.

Adjustments in Profit and Loss Account:
- The adjustment in the profit and loss account would involve reversing the effect of the initial recording of the sale. Since the sale was recorded as a credit to the sales account, the sales account should be debited with Rs.600 to cancel out the effect. This adjustment would result in a decrease in the reported sales and ultimately the net profit.

Adjustments in Balance Sheet:
- The balance sheet would also be affected by the adjustment. The initial recording of the sale would have increased the accounts receivable or trade receivables. To reverse this effect, the accounts receivable account should be debited and the returns inward account should be credited with Rs.600.

Explanation:
- The adjustment in the trading account is necessary to reflect the correct sales figure for the period. By debiting the sales account and crediting the returns inward account, the amount of the sale is effectively cancelled out.
- The adjustment in the profit and loss account is important to ensure that the reported net profit is not overstated. By debiting the sales account, the initial recording of the sale is reversed and the net profit is reduced accordingly.
- The adjustment in the balance sheet is required to reflect the correct accounts receivable balance. Since the goods sent on sale or return were not sold, the accounts receivable should be reduced by the amount of the sale. This is done by debiting the accounts receivable account and crediting the returns inward account.