Monday marks six months to the start of the Games with organisers saying ticket sales are between 12% and 15%.
Craven believe the next two months are crucial to ensure that athletes are not competing in front of small crowds.
"Obviously we have concerns and this was a key part of our latest project review in Rio last week," said Craven.
"But we have to accept that Brazilians don't buy tickets a year out or even six months out. It is something they do far nearer an event.
"While we know from research that 61% of Brazilian people believe tickets are too expensive generally, this is not the case with the Paralympics.
"There are two million tickets available for 10 Reals each (£2) and we have got to get that message out there.
"We are now working with the organising committee, the Brazilian National Paralympic Committee and the federal and city governments to launch a comprehensive plan to make the public aware of the great value for money.
"We want the Rio Paralympics to be the People's Games."
The Games, which will be the first in South America, run from 7-18 September with 4,350 athletes from 176 counties competing in 22 sports.
The Rio organising committee put 3.3m Paralympic tickets on sale in May 2015, hoping to surpass the 2.7m tickets sold that made London the best-supported Paralympics ever.
But Craven is aware that a lot of work still needs to be done ahead of the start of the Olympic Torch Relay in early May, when much of the media and publicity attentions will focus back onto the Olympics, which is also suffering from disappointing ticket sales.
"Each Games is its own Games and inspires a new group of people in a different part of the world and it continues to inspire the world through TV coverage," he told BBC World Service.
"We are confident that, in these next crucial two months before the Torch Relay starts, we will have great success with ticket sales and can follow London and Rio and will have just as great a Games.
"We are saying to the people of Brazil and Rio that this is the opportunity of a lifetime."
International Paralympic Committee president Sir Philip Craven says he is worried about the low take-up of tickets for the Rio Paralympics.