GST registration is mandatory for all types of online services providers, including bloggers, freelancers and affiliate marketers, given that they fulfil the following conditions:

Annual turnover is more than Rs 20 lakh (Rs 10 lakh for the Reserved States)
And
a- The person/company is involved in the online selling of information or database access/retrieval services within India.
b- The person/company is involved in the online selling of information or database access/retrieval services to an unregistered person in India from an outside country (Import of information by an unregistered person).
c-The person/company is involved in the online selling of information or database access/retrieval services from India to an outside country (Export of information).
As you can see, GST registration is mandatory for all service providers who make an annual sale of worth more than Rs 20 lakh, irrespective of their locations. However, GST applicability rules depend on the location of the services provider.

Source: CBIC