The Republican National Committee and the White House went to considerable lengths yesterday to bring Main Street to Capitol Hill.

The occasion was President Reagan's rally in support of a constitutional amendment mandating a balanced federal budget. It is an issue, the president said, that has broad support among the kind of people who "live on Main Street."

Many in yesterday's crowd of 5,000 said they were there because they had been given tickets to the event when they bought soft drinks at the Smithsonian over the weekend. Others had accepted tickets from GOP volunteers as they passed through the Capitol South Metro station.

The White House gave tickets to congressional aides, employes of various nonprofit agencies, federal workers, and 100 teen-aged girls who happened to be in town with the American Legion Women's Auxiliary.

The RNC, meanwhile, paid for 2,500 mailgrams to be sent to party stalwarts and contributors informing them of the rally, and committee volunteers roamed the museums and monuments around the Mall distributing tickets.

As the spectators passed through metal detectors into the area where Reagan was to speak, young RNC volunteers offered them hand-painted signs that said things like "We're For Ron" and "Yes Budget Amendment" to wave in front of the president and the television cameras.

Some people apparently brought their own signs. These, clearly in the minority, said things like "Jobs, Not Bombs," "Save Our Democracy: Vote Democratic," and "Israel, Free Lebanon."

The people who waited to hear Reagan and Vice President Bush in the sweltering heat clutched in their hands red, white or blue tickets asking them to "Join Ronald Reagan" at 12:15 p.m. It was red tickets for high-ranking federal employes and Republican National Committee faithful (they got to sit closest to the speaker's rostrum); blue for the rest of the federal work force and congressional aides; and white for the people who got their tickets on the street.

David Delgado, an administrative assistant at the National Association of Secondary School Principals, said he thought he had something to write home about when he got one of the blue tickets sent over to the association from the White House. Then he saw visitors at the Smithsonian this weekend getting a ticket with their purchase of a soft drink.

"To play this thing up as support for the president would be really bad," Delgado said. "People are here to see the president. They don't really know much about the amendment, at least the people I've talked to."

Maryland Attorney Craig Poff said he knew about the proposed amendment, but came mainly to see Reagan. "He's got lots of new one-liners," Puff said, citing this presidential quip: "Balancing the budget is like protecting your virtue, you just have to learn to say no."

Many began walking away from the Mall while Reagan, in the middle of his speech, was calling the drive for the constitutional amendment "a people's crusade."

At about 11:30 a.m. yesterday, four buses pulled up at the Environmental Protection Agency and the Department of Health and Human Services to carry federal employes to the site. But neither the White House nor Republican National Committee officials were able to say who had provided the buses. EPA's spokesman didn't know either, and a spokesman for HHS couldn't be reached.

White House and GOP officials said attendance at the event was strictly voluntary. White House spokesman Anson Franklin said federal employes were expected to use their lunch hours if they wanted to attend the rally and make up any time they may have missed from work by staying later in the afternoon.

Franklin said the national committee paid for most of the expenses relating to the rally.