Hallicarnia albipectus

Hallicarnia albipectus (Walker, 1855), male
Gastropacha albipectus Walker, 1855. List Specimens lepid. Insects Colln Br. Mus., 6: 1395. Text at https://archive.org/details/listofspecimenso46brit/page/1395/mode/1up?view=theater
Polymona hamala Walker, 1855, Ibid., 6: 1422. Text at https://archive.org/details/listofspecimenso46brit/page/1422/mode/1up?view=theater
Halicarnia albipectus Walker; Barlow, 1982: 52.
https://v3.boldsystems.org/index.php/Taxbrowser_Taxonpage?taxid=208406
https://www.mothsofborneo.com/part-3/lasiocampidae/lasiocampidae_13_1.php
https://www.inaturalist.org/taxa/124985-Hallicarnia-albipectus

Hallicarnia bulens (Zerny, 1928) is an extralimital species from Indonesia that is best separated by male genitalia.
Zolotuhin, V.V. and Holloway, J.D., 2006. The Lasiocampidae of Sulawesi. Tinea, 19(3), pp.244-259. Fig. 13-14.

GI: Agree with ID. This flies in Garo Hills too ( I have it from Karwani)