Smithsonian institute started tiger ecology project in Asia in early 1970s. The radio collared tigers and tracked them. The first tiger was radio-collared in Nepal which I know but I want a literature which mentions this.
Habib, B., Shrotriya, S., Sivakumar, K., Sinha, P. R., & Mathur, V. B. (2014). Three decades of wildlife radio telemetry in India: a review. Anim Biotelemetry, 2(4).