There are 2 ways to join as seller on ONDC network:
1. Get onboarded through one of the existing seller applications on the network (please go to the LINK to see list of Seller Applications).
2. Create your own Seller Application and join ONDC. Else, if seller does not wish to build an application from scratch, they can engage with a TSP who has an ONDC compliant App. Please refer to "ONDC Integration Guide" for more details.