Deductions under chapter 6 of the Income Tax Act in India refer to the various deductions that taxpayers can claim from their taxable income. These deductions are available under various sections of the Income Tax Act and are meant to encourage certain types of investments and expenditures that are considered to be beneficial for the economy or society. Here are some of the common key deductions available under chapter 6 of the Income Tax Act:

1. Section 80C: This section provides for a deduction of up to INR 1.5 Lakhs for investments and expenditures such as Public Provident Fund (PPF), National Savings Certificate (NSC), Life Insurance Premium, Equity-linked savings scheme (ELSS), Sukanya Samriddhi Scheme, etc.
2. Section 80CCC: This section provides for a deduction of contributions made to pension funds.
3. Section 80CCD: This section provides for a deduction for contributions made to the National Pension Scheme. (NPS)
4. Section 80D: This section provides for a deduction of up to INR 25,000 for health insurance premium payments made for self, spouse, and dependent children and INR 25,000 for health insurance premium payments made for parents.
5. Section 80DD: This section provides for a deduction of expenditure incurred for the maintenance of a disabled dependent.
6. Section 80DDB: This section provides for a deduction for medical treatment of specified diseases for self, spouse, children, and dependent parents.
7. Section 80E: This section provides for a deduction of interest paid on education loans for higher education.
8. Section 80G: This section provides for a deduction of donations made to specified charitable organizations and trusts.
9. Section 80GG: This section provides for a deduction of rental expenses paid by an individual who does not receive a house rent allowance (HRA) from the employer.
10. Section 80GGC: This section provides for a deduction of donations made to political parties.
11. Section 80TTA: This section provides for a deduction of up to INR 10,000 for interest earned on the savings account.
12. Section 80U: This section provides for a deduction of expenditure incurred for the maintenance of a disabled person.

It’s worth noting that the above-mentioned deductions are subject to certain conditions and restrictions, and the specific deductions and the amount of deductions available may vary depending on the specific section and the taxpayer’s personal circumstances. The deductions under chapter 6 of the Income Tax Act are meant to provide relief to taxpayers and to encourage certain types of investments and expenditures that are deemed to be beneficial for the economy or society.