Tax deduction is deductions are expenses you can deduct from your income, so that you only pay tax on the surplus. The more expenses you have, the less tax you will pay.
To clarify, a tax deduction does not equate to reducing the tax itself; rather, it involves deducting allowable expenses from your total income, which results in a lowered assessment of company profit and, by extension, a reduced tax liability on that adjusted profit. It is crucial to distinguish between the expense deduction and the direct deduction of tax.
In India it is the Income Tax Department who is in charge of tax.