President Reagan is to attend six events this week aimed at cementing support from Hispanic voters, and key aides said that support has surpassed their expectations by more than doubling in the last three months.

The increase has come since Reagan launched a series of meetings and speaking engagements with Hispanic voters.

"We're tapping the Hispanics who voted for us last time, and we are finding they are still there and we're betting there are more where they came from," a White House official said.

"In fact, we're doing so well we're surprised at how well we've been doing."

Reagan's top aides have said that Hispanic votes are crucial to the president's chances if he runs for reelection and that, without at least the 35 percent support given Reagan by Hispanics in 1980, mobilization of large numbers of anti-Reagan black and female voters could lead to his defeat.

Reagan's Hispanic support had dipped to a low of about 15 percent, according to White House aides. They said major Hispanic organizations, such as the League of United Latin American Citizens (LULAC),disparaged Reagan to Hispanic voters.

Since the president has begun making a point of speaking to Hispanic groups and inviting them to the White House, Hispanic support cited in polls reviewed by White House aides has increased to about 32 percent.

The latest round of meetings with Hispanics is to shift from right-wing groups--including staunch Republicans, veterans organizations and Cuban expatriates--and begin reaching out to Hispanic leaders who might lead Hispanic voters away from their traditional allegiance to Democratic candidates.

Among those coming to the White House this week are Hispanic educators, religious leaders, labor leaders and servicemen.

"Clearly, it's Hispanic week, and the president makes no apologies for it," White House spokesman Larry Speakes said.

The events are to begin today with Reagan leading a Rose Garden ceremony to mark the start of Hispanic Heritage Week, which the White House has announced as commemorating the "contributions Hispanic Americans have made to enriching American culture and life."

On Tuesday, the president is to meet with a group of Hispanic educators and, on Wednesday, host a ceremony celebrating his Caribbean Basin Initiative. Reagan has signed that trade incentive and tax relief plan, but the event is to include several ambassadors from Latin countries and allows Reagan to invite prominent Hispanics to the White House.

After that ceremony, the president is to meet at the White House with a group of Hispanic labor leaders and Hispanic journalists.

That night, Reagan plans to attend a dinner for the National Hispanic Assembly, a Republican Party group, at the Hyatt Regency in Crystal City.

On Thursday, the president is to meet with a veterans' group called Hispanic Service in American Defense.

In recent speeches to Hispanic groups, Reagan has dwelled on his administration's opposition to abortion and its backing for prayer in schools and a strong national defense against communism.

A White House aide said that Hispanics are "basically Republican in their beliefs, and we want to remind them of that. It's working for us."

However, in a television conference with a group of West Coast Republican leaders on Friday, Reagan said he realizes that, no matter what he does for Hispanics, many will not support him because several major Hispanic groups are "lined up with Democrats.

"So I don't think I'm going to be able to make much of a dent in them," he said.

LULAC, for example, recently released a study of the Reagan administration's record on Hispanic problems that showed increased poverty and unemployment among Hispanics under Reagan, and that criticized him for not appointing many Hispanics to government positions and for his military policies in Latin America.