The correct sequence is 4, 1, 2, 3.

• An Assistant Superintendent of Police (ASP) is a probationary rank in the Indian Police Force.
  • All Police officers start their career as an ASP.
• The Superintendent of Police (SP) is also known as Deputy Commissioner of Police (DCP).
  • The SP heads the police force of a district. 
  • He/she is responsible for maintaining the law and order in the district.
• The Inspector-General of Police (IGP) post is the third-highest rank in the Indian Police Force.
  • In many countries, it is the most senior officer of the entire national police force.
• Director-General of Police (DGP) is a high ranking police officer.
  • He/she is called State Police Chief.
  • He/she is appointed by the Cabinet from the Indian Police Service.

• The Indian Councils Act, 1861, by the British government laid the foundation of the Indian Police. It was called Superior Police Services, later known as the Indian Imperial Police.
• Following India's independence in 1947, it was renamed the Indian Police Service(IPS) in 1948.
• The IPS is one of the All India Services, along with the Indian Forest Service and Indian Administrative Service.
• Article 312(2) in part XIV of the Indian Constitution created the Indian Police force following independence.