Which of the following services is not included in the All-India Services (AIS) ?

At present, there are only three All-India Services (AIS) in India: the Indian Administrative Service (IAS), the Indian Police Service (IPS), and the Indian Forest Service (IFoS) [c1][t1]. The IAS and IPS were recognized by the Constitution at its inception, replacing the colonial-era Indian Civil Service and Indian Police respectively [c1][t2]. The Indian Forest Service was later established as the third All-India Service in 1966 under the provisions of Article 312 of the Constitution [c2][c3]. In contrast, the Indian Foreign Service (IFS) is classified as a Central Civil Service (Group A), not an All-India Service [c5]. While members of the AIS serve both the Central and State governments by turns, members of the Indian Foreign Service serve exclusively under the Union government, primarily in the Ministry of External Affairs and Indian diplomatic missions abroad.

Sources

1. [1] Indian Polity, M. Laxmikanth(7th ed.) > Chapter 74: Public Services > All-India Services > p. 545
2. [2] https://en.wikipedia.org/wiki/All_India_Services
3. [3] Indian Polity, M. Laxmikanth(7th ed.) > Chapter 15: Centre-State Relations > El l AtI~lndia Services > p. 150
4. [4] Laxmikanth, M. Indian Polity. 7th ed., McGraw Hill. > Chapter 15: Centre State Relations > El l AtI~lndia Services > p. 150
5. [5] Indian Polity, M. Laxmikanth(7th ed.) > Chapter 74: Public Services > Central Services > p. 546