The Senate Armed Services Committee voted yesterday to delay the Reagan administration's proposed 3 percent military pay raise six months, from July to January, as it moved to conclude its markup of the fiscal 1986 defense authorization bill.

During its daylong closed session, the panel also defeated by one vote a plan by Sen. Warren B. Rudman (R-N.H.) to cut 175,000 military and civilian employes from the Pentagon payroll. Instead, the committee voted to fund only 60 percent of the personnel increases sought by the Pentagon.

President Reagan proposed raising Navy and Air Force active duty forces by 27,000 and the civilian payroll by 18,000.

When the committee recessed last night, it was discussing an amendment by Chairman Barry Goldwater (R-Ariz.) to permit the secretary of defense to close any military base without obtaining an environmental statement, as now required by law, if the federal budget is in deficit.

A spokesman for Rudman said last night that, because of the close vote on his proposal to cut military personnel levels, he "probably" would offer the proposal again when the authorization measure is taken up on the Senate floor.

Other Senate sources said the Rudman idea found surprising support among both Republicans and Democrats looking for ways to cut defense spending.

At a Senate Appropriations subcommittee hearing yesterday, Assistant Secretary of Defense Lawrence J. Korb was asked about the Rudman proposal. He replied that "if we are given a free hand to manage the department the way we want," both civilian and military personnel reductions could be made.

Korb said one step Congress could take would be to pass the Goldwater base-closings amendment, eventually allowing a cutback in both military and civilian employes.

He said Defense Secretary Caspar W. Weinberger had not proposed any base closings to Congress since he came to office because he found that when "you announce you're going to close one, the people get all excited, and then you find you can't do it because of the difficulty" in obtaining congressional approval.

He added that few base closings ever took place in the Carter administration after then-defense secretary Harold Brown sent a list of suggestions to Capitol Hill.

Korb said the committee's vote to delay the military pay raise could save $600 million. At the same time, however, he said if personnel could not keep up with inflation, recruiting would be impeded.

Although the committee has no control over civilian pay levels, it in effect voted to freeze Defense Department civilian pay at current levels by refusing to count savings that would have resulted next year if a Reagan administration plan for a 5 percent pay cut eventually passed Congress.

"Members said that just won't happen," one source said yesterday, "so those funds could not be counted as available."

The committee approved limited funding for the Army's controversial Divad battlefield antiaircraft gun but refused to release the money without a report that the weapon had passed operational tests.

The panel also restored Navy funds for homeporting two new battleships at cities it chooses. Those funds, however, were to be made available only after the service justified the choices.