Please do consider the aspects I listed in my first comment on this thread.
Camping Trailer in a country like India is not recommended. Better to build one on a single body vehicle like Force Traveller, Tata Winger or something like Tata 407.
I think you've hit it right on the nail. We need sufficient secluded areas for these to work. And India with it's population, it seems a distinct impossibility. Besides the caravans would ideally be make more sense on the plains. and you have agricultural/private land all around our highways. Besides, would you really be willing to camp out in a unknown place, knowing that there's no police to protect you if things get ugly.
Well I have been asking around and I've come to know that all Indian oil petrol pump are to host such campers for a night hault.
One can camp in the wilderness by the day and find a good dhaba or petrol pump by the night to call it a day.
Suppose that two to three families or say two cars go together, then one can dare to camp in the open. I came to know that there are a few companies in Bangalore that offer camping space in locations all over India. I guess they have worked some sort of an agreement with the land owners to provide them with space.