Which communities in Assam wanted separate states for them in the later part of the 20th century?

All of the above.

The reorganization of the North-East was concluded by 1972; however, this did not mark the culmination of autonomy-related demands in the region. In Assam, various communities such as the Bodos, Karbis, and Dimasas expressed their desire for separate States. They pursued this demand through activities that included mobilizing public sentiment, engaging in popular movements, and even resorting to insurgency. In many cases, multiple communities claimed the same territory, making it impractical to continually subdivide the region into smaller states. Consequently, alternative provisions within our federal structure were employed to address their autonomy aspirations while remaining within the boundaries of Assam. Notably, the Karbis and Dimasas were granted autonomy through District Councils, while the Bodos were recently accorded an Autonomous Council.