The 'data' isn't specific to ESRI ArcGIS ( although there are a few special formats for DBs etc.). Geological hazards such as landslides are usually under the purview of whatever the geological survey agency is, at the national, state/provincial, metro, county, and city level, etc. ). 'North-East India is a vast area with varied terrain, so being more specific would be helpful. Do a Google Scholar search using the the obvious keywords like 'Landslide', 'GIS', and '(whatever location)'.

"NDMA guidelines are being followed for Landslide Hazard Zonation (LHZ) maps at 1: 50,000 scale and progressively larger scales for specific areas. National Remote Sensing Center (NRSC),Department of Science and Technology (DST), Council of Scientific and Industrial Research (CSIR), Indian Institute of India (IITs), Universities have done tremendous work in this regard. The NRSC Atlas on selected corridors of Uttarakhand and Himachal Pradesh has been a very useful Atlas (Please see NRSC work on Landslides). DST has funded more than 30 projects spread over India by various academic institutions the reports of which can be requested from DST (NRDMA)." from https://ndma.gov.in/Natural-Hazards/Landslide