Place of supply for pest control services to other state...

Can any one help me on below query.

We are registered under GST for 25 states excluding Daman, Dadra, and 7 sister states, but we are providing pest control related services in this states. so in this case

> Whether we need to charge IGST or CGST - SGST of that State and

> Do we need to take Registration in said States where we do not have any branches.