President Reagan has requested $100.9 million for the National Endowment for the Arts and $96 million for the National Endowment for the Humanities in his fiscal 1983 budget, which goes to Congress today. Those figures represent a 30 percent drop from the current NEA budget and a 26 percent drop from current NEH funding.

As expected, no funding is requested for the Institute for Museum Services, an agency that makes grants to institutions from art museums to zoos. Reagan had asked for a phase-out of the IMS in his fiscal 1982 budget message, but Congress voted to fund $11.5 million. Reagan also appointed Lilla Tower, an attorney and the wife of Sen. John Tower (R-Tex.), to direct the agency, a move that had been seen by the arts community as an administrative show of support for the IMS.

"These reduced levels of funding," says the president's budget message, "reflect the administration's intent to encourage direct beneficiaries and the private sector to make larger contributions to cultural activities."

However, many in the arts community and some business executives doubt that the private sector -- particularly corporations -- will give much more to cultural activities, especially with social and educational organizations competing for more charitable contributions.

The National Council on the Arts, which held its quarterly meeting here this weekend, was given a breakdown of the president's requested NEA budget during a closed session. The council -- the presidentially appointed body that advises the NEA -- is on record as supporting a $149 million budget for the NEA in fiscal 1983.

The president's NEA budget would break down as follows:

* $69.8 million for program funds; 20 percent of this would go to state arts agencies.

* $11.1 million for the Treasury funds grant program.

* $7.4 million for challenge grants.

* $12.6 million for administration.

Although, the proposed fiscal 1983 budget is 30 percent lower than the current NEA budget, the fiscal 1983 administrative figure is higher than the current figure of $10.9 million. NEA officials say that $1 million of that increase is for the higher rent the agency will pay when it moves into the Old Post Office building with the NEH.

In addition to budget talk, NEA chairman Frank Hodsoll announced to the council two new endowment appointments: Frank Conroy, the author of a 1967 autobiography of childhood, "Stop-Time," as director of the literature program, and Marvin Liebman, director of his own New York public relations firm and a fund-raiser for conservative causes, as director of public affairs.

Other items discussed during the council meeting was Hodsoll's plan to hold seminars around the country to discuss the state of the arts and the needs of artists. There would be one two-day seminar on each NEA program category. This part of the council session was closed to the public, also.

"We were discussing the budget which originally was embargoed to the public until today, but because of leaks was released Saturday ," said Hodsoll when asked why the session was closed, "and then we went into discussion of the seminars. I guess that's why."

However, Hodsoll did sum up some of the council's discussion of the seminar plan. "Some people suggested that we not make too much of them," said Hodsoll. "Some said, 'Let's not supplant the panels.' Some suggested that we wouldn't find out much in two days. Some were worried about the cost."

Hodsoll said he had not figured out what the cost would be. The first seminar, on design, is scheduled for Feb. 19-20 in Charlottesville. Participation is by invitation.