air /rail travel agent

Saif Ali (Student) (132 Points)

13 August 2017  
person registered as an agent with two entity.
1. irctc :where he recieves commision from irctc for rail booking done ,at fixed interval.
2. another portal:for flight booking. the reciept is generated for example of rs. 100 to the actual customer. but the agent has to pay say for example rs. 80.means rs.20 is the amount he earn.

what are the gst implications for such agent.
because he is niether an aggregator to levy gst. nor he is liable to collect tcs as per section 52.
but the portals are asking him to get register u/s 24 (vii)
so please provide me the info. what are the obligation on him