Who among the following believed that the princely states should be free to choose their own course in deciding whether to join India, Pakistan or remain independent?

The Muslim League.

Government’s Approach towards Partition & Princely states:

Prior to Independence, the British announced that with the end of their rule, the paramountcy of the British crown over the Princely States would also end.
This meant that the Princely States, numbering 565, would become legally independent and could choose to join India, and Pakistan, or remain independent.
The decision of joining India or Pakistan was left to the princely rulers, rather than being determined by the people.

The interim government firmly opposed the division of India into small principalities.
The Muslim League differed from the Indian National Congress, advocating for the states' freedom to choose their own course.
Bringing the princely states together was complex and required skilful persuasion, considering many shapes and different administrative structures.
Sardar Patel, India's Deputy Prime Minister and Home Minister, played a crucial role in diplomatically negotiating with the rulers of princely states and integrating them into the Indian Union.