The real estate industry is bruised and angry. "I don't think it'll be difficult to mount a thundering herd to carry our message," said Wayne Thevenot, president of the National Realty Committee.

The Individual Retirement Account lobby is assembling, in the words of one of its lawyers, "a full-court, no-holds-barred, money-is-no-object" assault.

States, counties and cities plan to do "whatever we can" to restore the sales tax deduction, according to one of their Washington lobbyists.

In the two days since the Senate Finance Committee passed a radical tax-overhaul bill -- one touching almost every business and taxpayer -- groups that stand to lose tax benefits have begun planning the fight of their lives.

The battle on the Senate floor, expected to begin in early June, is shaping up as a clash of titans. Some of the country's most powerful lobbies are throwing all of their resources against the committee's bill, while other influential business groups support it.

President Reagan entered the fray yesterday, White House officials said, telephoning key Senate leaders to press for early consideration of his chief domestic policy initiative, effectively taking on some of the business groups that have supported him strongly.

"The American people deserve the type of reform that you have put together," Reagan was reported to have said in his call to Finance Committee Chairman Bob Packwood (R-Ore.), the bill's chief architect.

The Finance Committee's bill, which passed unanimously in Wednesday's early hours, would redistribute many benefits of the existing tax system.

Corporations would pay about $100 billion more in taxes by 1991; individuals would pay that much less. A wide range of deductions and credits would be eliminated -- and tax shelters would be vastly curtailed -- in exchange for slashing tax rates for all and removing 6 million poor people from the tax rolls.

Because the proposal would make so many changes in so many areas of economic life, many business groups and people expressed bewilderment yesterday about whether to oppose or support it.

The computer industry likes the tax credit for research but is wary of the elimination of low rates on capital gains. General Motors, which likes the low corporate tax rate, worries about the elimination of interest deductions for auto loans. A wide range of wealthy executives blanched at repeal of the investment tax credit but drooled over a top individual tax rate of 27 percent.

"In terms of political tactics, this bill is almost a masterpiece," said Paul Huard of the National Association of Manufacturers, remarking on the competing interests the measure has unleashed.

Real estate is one industry that has no doubts, however. Thousands of members of the National Association of Realtors and the National Association of Homebuilders plan to come to Washington in the next week and to spend much of their time lobbying senators to oppose a provision aimed at wiping out some real estate tax shelters.

"The impact of this bill is so draconian on some people in this field that it is not difficult to get them to react," Thevenot said. "Once you explain it they are incredulous.

"We feel abandoned by our friends," Thevenot continued. "In the words of the old country music song, they left footprints on our stomachs when they walked out on our hearts."

Thevenot said his group of developers, which is working closely with Realtors and house builders, will call on influential members to "draw on their access" to make the industry's case.

The Investment Company Institute, heading the campaign for IRAs, has placed advertisements in 70 newspapers and on television and radio. More are planned, in hopes that constituents will call senators' offices to protest the proposed cutbacks in the deduction for IRA deposits.

The Finance Committee bill nicked 401(k) tax-deferred savings plans, but some of the plans' proponents fear they could lose more if the Senate restores full IRA deductions. But IRAs and 401(k) plans are not the only competing interests.

"In one sense, everybody is in competition," said Bob Chlopak, lobbyist for the sales tax deduction. "There is only a limited amount of dollars."