If you had not explained about the credited cash in your bank account in the previous year then you ought to return the substantial tax if the IT dept has found the same. Under the section 69A for income tax if you have no answer for the money, gold, jewellery and another valuable item in the preceding year which is not shown in the account, or either Assessing Administrator is not convinced by such expression, then all these assets will be the income of the taxpayer for the preceding year.
All these earned income whose explanation is not given will be deemed with high income tax at the rate
Above the assets like money, gold and other valuable items, any cash found in the books of a taxpayer whom he has no explanation or the officials on asking have not been found satisfied than a heavy tax at the mentioned rate will be charged. These entries are known as unexplained cash credit under section 68 of the income tax.
Read Also: Revisit History of Income Tax Slabs (1944-45 to 2020-21) in India 
Several taxpayers deposited huge cash in their accounts but in 2017 when the demonetisation was announced and various accounts have come under scrutiny. The Income Tax department then asked to settle all the undisclosed accounts without any question on the undisclosed incomes.
