The native State of Tripura became involved in the Freedom Movement early in the 20th century because

Tripura’s entry into the freedom movement was rooted in earlier local resistance: the region witnessed 19th-century uprisings (Tipra 1850, Kuki 1860–61, Jamatia 1863) and ongoing socio-political contests that show an existing tradition of opposition to local authority and outside interference [1]. By the early 20th century these strands matured into organized anti-feudal and anti-colonial activity—tribal and non-tribal mobilization, peasant agitation, and political group formation (e.g., Tripura Rajya Gana Parishad)—which targeted both the monarchy’s feudal practices and British protectorate policies, thereby drawing the princely state into the national movement [2].

Sources

1. [1] https://tripurauniv.ac.in/site/images/pdf/StudyMaterialsDetail/BA-4TH(History)-History%20of%20Tripura%20and%20Assam.pdf
2. [2] https://ijsdr.org/papers/IJSDR2502185.pdf