PASSAGE TO INDIA has been booked, and the first leg of the trip takes us to the National Gallery for "The Sculpture of India: 3000 B.C. to 1300 A.D."

With its corpulent gods and globular- breasted goddesses, the show kicks off the "Festival of India," a year-long cultural and scientific exchange planned by the late Prime Minister Indira Gandhi and President Reagan.

In India, for this sort of new endeavor, a prayer is offered to the god Ganesa, as happened this past Saturday before a statue of Ganesa in one of the exhibit halls. The prayer starts like this: "O God, who is pot- bellied, huge and with a luster that even a million suns do not have, remove all obstacles . . . ." This is quite complimentary, given that Ganesa is an elephant.

The show is in fact a convocation of the gods and the godlike, such as Siva, embodiment of opposites, who dances the universe in and out of being, and Visnu, who tells him when. Depicted here too are the nature spirits, both male and female, and seven mother goddesses -- a ninth-century sculpture shows four of them, generally lovely if you discount the extra pair of arms on one and the boar's head on another.

Then meet the Bodhisattva, the compassionate, on his way to becoming a Buddha, but choosing instead to mingle in the world and aid it in its suffering. And Buddha, the enlightened one.

The most haunting pieces in this hundred- item exhibit revere Buddha: as mere footprints on a throne, or, in a third-century torso, draped like a Greek statue. Buddha is also a smooth disembodied head with pointed brows and aquiline nose, or a face emaciated from fasting, with sunken eyes.

Others have all the fun. According to the sculptures, gods disport themselves with many attendants and are never without transport, be it water buffalo or mouse (as in the case of the elephant god).

A second-century Bodhisattva here looks like an 18th-century rou,e, with his curly long hair and moustache and half-closed eyes. "An Amorous Couple" leaves little to the imagination. But apparently their behavior is reserved, compared to some scenes depicted on temple walls back in India.

Fascinating and strange, it's a sculptural tradition that combines sensuality with religion. This same sensuousness is reflected in a sort of lush and lazy style. The early Indian sculptors just seemed to take a little longer to go around a curve.

THE SCULPTURE OF INDIA: 3000 B.C.-1300 A.D. -- At the National Gallery of Art through September 2.