For a more automated approach, the gadm Python package can dynamically fetch data directly into a geopandas DataFrame:
The central repository for version 3.6 is hosted on the GADM website via the legacy page. You can access the downloads through the following links: download gadm data version 36 work
The traditional format. It consists of a group of files per administrative level. It is widely compatible but comes with file size limitations. For a more automated approach, the gadm Python
GADM data is natively provided in geographic coordinates (WGS84, EPSG:4326). If you need to calculate accurate surface areas or distances, project your layers into a local Projected Coordinate System (like UTM) first. To help find the exact data you need, please let me know: Which country or region are you mapping? It is widely compatible but comes with file size limitations
This comprehensive guide will walk you through downloading GADM data version 3.6 and step-by-step methods to work with it effectively in your spatial projects. Part 1: How to Download GADM Data Version 3.6
The recommended modern format. It contains all administrative levels in a single file database.