Why has the government made registering mobile phones’ IMEI numbers compulsory?

The International Mobile Equipment Identity (IMEI) is a 15-digit number that is unique to every device. Mobile manufacturers in India will have to register the number of every handset with the government. With this, the location of a phone can be identified

from https://www.firstpost.com/explainers/india-registering-mobile-phones-imei-numbers-compulsory-11350211.html