... I don't think Leonard Orr took his "hyperventilate till your system overloads" technique from India. It's not Breath of Fire, for instance, though they try to say there's a connection. I think Orr made most of it up, then tried to make it seem more ancient by pretending it was from India. His rebirthing crew misappropriated and misrepresented all kinds of things about Hinduism and Hawaiian Indigenous religion. They incorporated all kinds of terminology from the fraudulent "Huna" books.
The rebirthing people are dangerous. They pretend to be psychologists, and some of them dish out half-baked Freudian oppression around birth and gender issues. But to be a rebirther you only have to take a few seminars, then go through ten sessions of rebirthing yourself, you do not need any kind of training in psychology or psychiatry.
The group is cultish, and encourages people to cut ties to their family and friends, and to consider their pay-to-hyperventilate comrades their new family. They mess with people's minds and rip them off for huge quantities of money.
We have a number of threads here that mention rebirthing. Go back to the main page and use the Search box.
And please, be careful; those people are messed up.