I am doubtful that such data exists easily available, maybe if you have good contact with forestry officials , but maybe in the following publications you can get some trace......

Gupta, A. K. (2000). Shifting cultivation and conservation of biological diversity in Tripura, Northeast India. Human Ecology, 28(4), 605-629.

Dasgupta, M. (1986). Jhumias of Tripura. Economic and Political Weekly, 1955-1960.

Dev Varman, S. B. K. (1971). A Study over the Jhum and Jhumia Rehabilitation in the Union Territory of Tripura'. Directorate of Research, Government of Tripura, Agartala.

Das, S., & Das, M. (2014). Shifting Cultivation in Tripura–A Critical Analysis. Journal of Agriculture and Life Sciences, 1(1).

Debnath, A., Debnath, J., Ahmed, I., & Pan, N. D. Change detection in Land use/cover of a hilly area by Remote Sensing and GIS technique: A study on Tropical forest hill range, Baramura, Tripura, Northeast India. http://www.ipublishing.co.in/jggsarticles/volseven/EIJGGS7024.pdf

Debnath, J., Das, N., Ahmed, I., & Bhowmik, M. (2017). Chronological Change of Land Use/Land Cover of the Muhuri River Basin from 1972 to 2016, Tripura, North-East India. Indian Journal of Science and Technology, 10(22).

http://www.indjst.org/index.php/indjst/article/download/112067/80500

Paul, S., Tripathi, A. K., Burman, R. R., Panggam, M., Ray, S. K., Kalita, N., ... & Singh, A. K. (2017). Jhum cultivation and its consequences on forest and environment in Eastern Himalayan tract of India: a participatory assessment. Range Management and Agroforestry, 38(1), 121-126.

Article Jhum cultivation and its consequences on forest and environm...

Barthakur, B. J. (2017). Shifting Cultivation in North-East Region. Artha-Journal of Social Sciences, 4(2), 68-78.

http://journals.christuniversity.in/index.php/artha/article/download/837/775

Sengupta, M. (2017). Gender, tribe and development: a case study of the Reang tribal community in Tripura (Northeast India). Asian Ethnicity, 1-21.

Hanglem, A. (2017). Organic Farming in Manipur: Benchmark Status, Motivational Factors and Livelihood Impact (Doctoral dissertation).

http://krishikosh.egranth.ac.in/bitstream/1/5810028283/1/Amita%20Hanglem-phd.pdf

good references Eberhard Weber . As shifting cultivation is implicitly restricted by GOI and so forest department or any government agencies will not reveal the data. Yes you can get help of NGOs or other local agencies working in field to get the information from scratch.