The Central Board of Direct Taxes (CBDT) and the Central Board of Indirect Taxes and Customs (CBIC) are two important authorities in India responsible for the administration and enforcement of direct and indirect taxes, respectively.

**Central Board of Direct Taxes (CBDT)**

Composition:

* The CBDT is a statutory body established under the Income-tax Act, 1961.
* It consists of a Chairman and 15 members, who are appointed by the Central Government.
* The Chairman is the administrative head of the CBDT.

Powers:

* The CBDT has the power to:
+ Issue circulars, notifications, and instructions to clarify tax laws and regulations.
+ Approve or reject appeals filed by taxpayers against orders passed by the Income-tax Appellate Tribunals.
+ Conduct inquiries and investigations into suspected cases of tax evasion.
+ Frame rules and regulations under the Income-tax Act.
+ Approve or reject applications for consent to compromise or settle tax disputes.

Functions:

* The CBDT is responsible for:
+ Administering and enforcing direct taxes, including income tax, wealth tax, and fringe benefits tax.
+ Collecting taxes and fees from taxpayers.
+ Providing guidance and clarification on tax laws and regulations to taxpayers and other stakeholders.
+ Conducting audits, surveys, and investigations to detect and prevent tax evasion.
+ Monitoring compliance with tax laws and regulations.

Role in mobilizing government revenue:

* The CBDT plays a crucial role in mobilizing government revenue through direct taxes.
* It ensures that taxpayers comply with tax laws and regulations, which helps to increase government revenue.

**Central Board of Indirect Taxes and Customs (CBIC)**

Composition:

* The CBIC is a statutory body established under the Central Goods and Services Tax Act, 2017 (CGST Act).
* It consists of a Chairman and 12 members, who are appointed by the Central Government.
* The Chairman is the administrative head of the CBIC.

Powers:

* The CBIC has the power to:
+ Issue circulars, notifications, and instructions to clarify GST laws and regulations.
+ Approve or reject appeals filed by taxpayers against orders passed by the Authority for Advance Rulings (AAR) or Appellate Authority for Advance Rulings (AAAR).
+ Conduct inquiries and investigations into suspected cases of GST evasion.
+ Frame rules and regulations under the CGST Act.
+ Approve or reject applications for advance rulings.

Functions:

* The CBIC is responsible for:
+ Administering and enforcing indirect taxes, including goods and services tax (GST), customs duties, and central excise duties.
+ Collecting taxes and fees from taxpayers.
+ Providing guidance and clarification on GST laws and regulations to taxpayers and other stakeholders.
+ Conducting audits, surveys, and investigations to detect and prevent GST evasion.
+ Monitoring compliance with GST laws and regulations.

Role in mobilizing government revenue:

* The CBIC plays a crucial role in mobilizing government revenue through indirect taxes, including GST, customs duties, and central excise duties.
* It ensures that taxpayers comply with GST laws and regulations, which helps to increase government revenue.

In conclusion, both CBDT and CBIC play vital roles in administering and enforcing direct and indirect tax laws respectively. They are responsible for ensuring compliance with tax laws, collecting taxes, providing guidance to taxpayers, conducting investigations, monitoring compliance, and mobilizing government revenue. Their efforts help to increase government revenue, which can be used to fund public expenditures that benefit society as a whole.