To register your self on DLT platform, you need to talk to your operator (BSNL, Videocon, MTNL, Airtel) they will provide you a link where in your need to fill your basic details and have to upload the your KYC documents.
How to Registered on DLT platform
At time of registration you need to choose telemarketer option or enterprise option. You also need to pay certain fees depending upon your category or business.
A Full Guide Of Step By Step DLT Registration Process
Department of Telecommunications
Direction dated 20 Jan 2020 on implementation of TCCCPR 2018