Lets get one thing straight, importing a quad ( irrelevant of condition) is a bad idea.
Every parcel gets handled by india post the moment the aircraft lands in india. That may not be the case for DHL and FeDEX.
All parcels other than these will be delivered by your usual "cycle man".
The registered airmail ( handled by india post) may skip customs while the DHL/ FedEx will incur customs.
From what you state, both the sellers on the respective websites are using the same method. I. E registered airmail .
Regards
I want to buy Eachine e50 pocket drone
P. S - Are you trying to buy a U. S Air Force Predator Drone? No. Then what is the problem in calling it a multirotor/quad?