By his own definition, James T. McIntyre will be a nuts and bolts budget director, in the traditional style, with little of the high visibility of his predcessor, Bert Lance.

At a briefing yesterday at the Office of Management and Budget, McIntyre went round the room and shook hands with reporters, in the best Bert Lance style.

But there the similarity ends. Low key and almost self-effacing, McIntyre says he "will stay more involved in the day-to-day workings of the OMB." He adds, hastily, that this comment is not meant to be as reflection on Lance, who critics said was more interested in high-level politics than the intricate numbers work at OMB.

But there is a tough edge underlying McIntyre's calm demeanor. "We'll run a fairly tight ship around here," he promised yesterday. He also said that he is not afraid to talk up to the President.

"I don't mind telling him what I think," McIntyre said, "because that's what he has me around for." he concedes. However, that his relationship with Carter, which goes back to early 1970, has been more professional than personal and social.

Asked whether the appointment of yet another Georgian to a high post doesn't emphasize the tight control of the so-called "Georgia Mafia," McIntyre said he hoped he would be judged by his record rather than his place of birth.

McIntyre, who is likely to face closer congressional scrutiny than did Lance at the time of his appointment, joked that he only "sticky point" in his background "is that my net worth is so small."

The financial statement he and his wife submitted last January when he was appointed deputy showed a net worth of $100,139. He said yesterday the only change he knew of was acquisition of a house - and a substantial mortgage - in Virginia.

McIntyre said he has been and intends to keep in touch with business leaders, but conceded he would not play the unique Lance ambassadorial role. "There are a number of people in this administration who relate to and deal with with business," McIntyre said, " and I feel that's a healthy thing.

Irving S. Shapiro, DuPont Co. chairman and cochairman of the influential Business Rountable, praised McIntyre yesterday as "a very able professional "who could work well with the business community.

McIntyre is credited by associates in the Cabinet with doing most of the hard work of preparing the budget, even during the time Lance was in office. He was heavily involved in Georgia state budget affairs, but acknowledged yesterday that he "had had to study hard on the defense and foreign areas" in the national budget when he come in as Lance's deputy.

Although he declined yesterday to forcast the exact budget totals for fiscal 1979 - which he indicated would be subect to a final review today - McIntyre hinted that published reports of a budget in the vicinity of $500 billion in expenditures, with a $60 billion deficit, were about right. In "real" terms, he said, the spending figure would be up only 2 or 3 per cent over fiscal 1978.

It's "so close" to $500 billion, he said, that it's impossible to tell yet whether the total will edge over or slip under the mark.

He did reveal, however, that the dificit for the current year, fiscal 1978, would be about $59 billion, without counting some supplemental appropriations that could add to that figure.

When reminded that the administration had earlier set as a target a much smaller budget deficit for fiscal 1979 than in 1978. McIntyre pointed out that a $60 billion deficit for next year would be a consequence of the President's decision to ask for a big tax cut to stimulate the economy. Administration souces last week estimated the tax cut proposal at $25 billion, beginning next Oct. 1.

McIntyre said the fact that a larger budget deficit in fiscal 1979 would be created by a tax cut rather than increased spending puts the matter "in a different light."

He said that the President is sticking to his goal of reducing government expenditure from 23 per cent of gross national product to 22 per cent in fiscal 1979, and to 21 per cent in fiscal 1981.

On the subject of government reorganization, McIntyre said he would take personal charge of the effort, and that Carter would summit at least six major reorganization plans to Congress next year, including personnel, civil rights and law enforcement areas.

He also hinted boardly that the President would submit a proposal for a separate Department of Education, but indicated decisions had not been made on what the department would be composed of.