The parents of a 13-year-old boy who suffered serious brain damage in an Arlington swimming pool accident 17 months ago will receive $5.6 million in a settlement reached while a federal court jury in Alexandria was deliberating the case late Tuesday.

The youth, Anup Sharma, described in court testimony as a gifted student enrolled at New York's Bronx High School for Science at the time of the incident, is expected to live out his life in a vegetative state in a New Jersey hospital for long-term patients, a lawyer for the parents said yesterday.

Sharma, who moved to New York from India with his parents in 1979, was discovered at the bottom of a pool at Dominion Arms, an apartment complex at 333 S. Glebe Rd., where he had gone to swim during a visit with relatives in August 1981, according to testimony.

No one apparently knows what caused the accident. Medical records introduced at the trial indicated that Sharma had been in excellent health at the time.

The youth, who was without oxygen for an estimated 10 to 15 minutes, was revived by Arlington rescue squad members, but spent the next four weeks in a coma at Arlington Hospital, the plaintiffs' lawyer, Joel M. Finkelstein, said.

"He's now awake. His eyes are open, he can see light, he can feel pain. But he's fed through a tube in his stomach. He's mostly in the fetal position and he's in the infant stage mentally," said Finkelstein.

The youth's care is expected to cost $1.2 to $1.7 million, according to testimony at the trial. About a third of the $5.6 million award will go to attorneys' fees, Finkelstein said.

The two-day trial in U.S. District Court in Alexandria included a 20-minute videotape presented by the plaintiffs titled, "A Day in the Life of Anup Sharma," that detailed Sharma's current condition at Roosevelt Hospital in Metuchen, N.J.

Sharma's father, an auditor employed by the New York State Insurance Department, visits his son every evening and on weekends, Finkelstein said. His mother spends every day at the youngster's bedside.

Named as defendants in the case were Kaus and Whitestone Inc., whose Dominion Aquatics division furnished lifeguards and pool maintenance at the complex, and Snell Construction Co., owners of Dominion Arms. Two teen-age lifeguards, Elizabeth T. Vick and Elizabeth F. Roach, also were made defendants at the request of Kaus and Whitestone.

James Gregg, a lawyer for Kaus and Whitestone, refused to discuss the case yesterday. Insurance companies for the pool maintenance firm are expected to pay the bulk of the settlement, according to Finkelstein.

The Sharma youth was spotted lying under water by Sean Johnson, a teen-ager who was on the diving board waiting for Sharma to move out of the way, witnesses testified. First Johnson's brother and then Johnson jumped into the pool to get Sharma to move. When Sharma remained on the bottom, the Johnsons alerted lifeguards.

Former University of Maryland swimming coach William Campbell, appearing as an expert for the Sharmas, testified that Vick and Roach were poorly positioned at the pool and departed from standard lifesaving techniques in their rescue attempt. The defense denied the allegation.

Sharma had no pulse and was not breathing when rescue squad members arrived, according to testimony. He was revived with cardiopulmonary resuscitation and rushed to the hospital, Finkelstein said.