More than 200 high school and college students who jammed a hearing on bills to raise Virginia's drinking age had one message today for Virginia lawmakers: 18-year-olds should be allowed to drink beer in bars and restaurants.

But the students and their supporters, including a Norfolk-based group called Many Against Drunk Driving (MADD), encountered a top Reagan administration official who joined with a Northern Virginia group--also called MADD, Mothers Against Drunk Driving--in advocating raising the state's drinking age to 21.

The MADD vs. MADD confrontation before the House General Laws Committee was the latest turn to an issue that has become one of the most popular in this election-year legislative session.

The committee delayed its vote on the issue until Monday, but many legislators expect the committee and the General Assembly to approve raising the legal age for drinking during the current session.

Today both MADD groups, whose supporters sported nearly identical large yellow buttons, agreed that Virginia should raise from 19 to 21 the age at which beer can be bought legally in grocery stores. But the Norfolk MADD group, supported by many Virginia restaurateurs, argued that 18-year-olds should be able to drink beer in bars and restaurants, provided they pass special alcohol education classes and stay out of trouble with the law.

Virginia now forbids the sale of wine and liquor to those under 21, but allows 18-year-olds to drink beer in bars and 19-year-olds to buy beer in grocery stores. Last week Gov. Charles S. Robb endorsed raising the drinking age to 21 as a way of reducing teen-age drunk driving deaths, which have jumped by 148 percent since 1974 when Virginia lowered the drinking age for beer.

"The 18-, 19- and 20-year-olds are not scatterbrains," said Susan Midgett, who founded the Norfolk MADD chapter two years ago after her 14-year-old son was killed by a drunk driver. "You can marry without parental consent at 18, join the military, you can carry firearms, but if you raise the drinking age, you'll be saying that these people can't have a beer."

Del. Floyd C. Bagley, a Prince William Democrat and one of nearly 700 persons who came to the hearing that was moved to a highway department auditorium to accommodate the crowd, said he plans to introduce a bill on behalf of Norfolk MADD.

"Not many people here know that I lost my only son 13 years ago to a drunk driver," Bagley said.

Others called the Bagley proposal unenforeceable and said that the best way to reduce teen-age drunk driving deaths is to raise the drinking age.

"It is unconscionable that we would allow the national disgrace" of teen-age drunk driving deaths to continue, said Jim Burnett, chairman of the National Transportation Safety Board.

Burnett reminded lawmakers that Maryland raised the drinking age to 21 last year and said that governors of North Carolina and West Virginia support moves to raise the drinking age to 21. Similar legislation soon will be introduced in the District, Burnett said.