In a year when many Republican congressional candidates are trying to grab ahold of President Reagan's coattails, Ray L. Garland has reached for the whole suit.

"The bottom line is this," says Garland, a former state senator who is striving to revive his political career Tuesday in Virginia's 6th Congressional District, "I'm for President Reagan and [Democratic Rep.] Jim Olin is for Walter Mondale."

Garland, 50, once known as one of the legislature's best orators, has downplayed his moderate views of the past and traded in his once flamboyant image of stylish cigarette holders and bowler hats for conservative suits to match his message.

Still, the former legislator, educated at the University of London, remains given to colorful, explicit language. And some of it has gotten him in trouble in the largely conservative, religion-oriented district, which is home to Moral Majority founder the Rev. Jerry Falwell.

The respected Congressional Quarterly sparked the biggest furor when it quoted Garland during the Dallas convention as comparing the Democratic Party to a "busted out, two dollar whore."

Garland did not deny the remark but said later he only was repeating the views of others. Still, Democrats had a field day with his statement, which was widely seen as tasteless and made some of Garland's supporters wince.

Just as the issue began to die, Garland fueled the controversy by mentioning the arrest on a drunk driving charge two years earlier of state Del. Clifton A. (Chip) Woodrum, a popular Roanoke Democrat. Garland then noted that he had not tried to make political mileage of Woodrum's arrest. (Woodrum was cleared of the charge.)

All of that "definitely slowed him down . . . derailed him for a certain period of time," said Gilbert E. Butler Jr., Republican chairman of Roanoke. "What the net effect is going to be is truly hard to tell."

Garland acknowledges that Olin is ahead, but he and other politicians say Garland may be within striking distance if Reagan boosts his totals in the district. "I need 80 percent of the Reagan vote and none of Mondale's to win," Garland said.

"If ever there is a year when coattails could have an effect," this would be it, said Democratic state Sen. Dudley J. Emick Jr. of Bototourt County. In any other year, Emick says Garland easily would lose.

Olin, 64, is a former General Electric executive who is completing his first term. He won in 1982 by about 2,000 votes out of 135,000 cast in a district that was represented for 10 years by Republican M. Caldwell Butler, a moderate who retired. Both sides expect more than 160,000 to people to vote this year.

Olin has stressed his independence in his Republican-leaning district, giving only token support to the national Mondale-Ferraro campaign.

Olin, who has kept up a steady stream of advertising, repeatedly visited the district and largely stayed out of major controversies, maintains a low-key campaign style, leaving most of the controversy to Garland -- making him the issue as much as Olin's record.

Garland has warmly embraced Reagan's conservative themes; for example, saying in commercials that he's "proud to be an American" while criticizing Olin for his initial reluctance to fully support the U. S. invasion of Grenada last year.

"Olin has been a mainstream, bread-and-butter Democrat who has thrown a few bones to business," Garland said during an interview. Later, he came back to the theme of his attack: "Olin is an authenic American liberal from the top of his head to the tip of his toes."

Garland's staunch conservative stands have surprised, bemused or angered some who remember his 16 years in the state General Assembly before his defeat in 1983.

In an editorial endorsing Olin, the Roanoke Times & World-News noted its past support for Garland. "But in this campaign, he has taken flight from his progressive philosophy and embraced an array of right-wing positions . . . ," the newspaper said. "Garland's willingness to compromise his principles in search of victory is not becoming in a man with his record and ability."

On issues, Garland and Olin have differed on how to curb the nation's budget deficits, foreign policy and a host of social issues. But Olin is generally given credit for paying attention to district issues.

Roanoke Mayor Noel Taylor recently endorsed Garland, but his announcement was indicative of Garland's problem.

Taylor warmly praised his fellow Republican, but then said: "Congressman Olin has done a good job for the City of Roanoke . . . . Jim Olin is a friend."