The real intention of the British to include the princely states in the Federal Union proposed by the India Act of 1935 was to

The Government of India Act, 1935 provision for an All‑India Federation gave the princely states disproportionate representation and allowed their rulers to nominate representatives rather than having popular elections; this arrangement ensured princes would act as a conservative bulwark against nationalist influence in the federal legislature, which itself was given limited real power [1]. The Act reserved a large block of seats for princes (e.g., substantial allocation in the Federal Assembly and the Council of States), reinforcing their role as appointed counterweights rather than genuine partners in democratic governance [2]. Thus the primary British intent was to use princes to counter‑balance anti‑imperialist nationalist forces.

Sources

1. [1] Modern India ,Bipin Chandra, History class XII (NCERT 1982 ed.)[Old NCERT] > Chapter 15: Struggle for Swaraj > The Government of India Act, 1935 > p. 291
2. [2] Rajiv Ahir. A Brief History of Modern India (2019 ed.). SPECTRUM. > Chapter 34: The Indian States > V. Policy of Equal Federation (1935-1947): A Non-Starter > p. 607