House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.) said yesterday that proposed changes in House management would "sail through" the body even though opposition was voiced at the House Democratic Caucus.

In a session with reporters after the morning caucus, O'Neill did concede there "may be modifications here and there" when the proposal reaches the floor, probably Oct. 11.

Rep. Jack Brooks (D-Tex.), who chairs the House Government Operations Committee, warned at the caucus that "next November you'll have to answer opponents who charge you have voted yourselves $12,000 to win a computerized campaign, additional staff and worldwide travel with your secretary."

Proposals in part call for establishment of an administrator to handle day-to-day management of the House; an auditor to review House spending; revised travel rules; establishment of a $12,000 allowance for each member to be used for computer operations and a controversial system for handling discrimination complaints from House employees.

With a handful of members nodding approval, Brooks called the rules changes "arbitrary and inconsistent" in a speech often jabbing satirically at "reformers."

Rep. David Obye (D.Wis.), chairman of the commission that drafted the proposals, ticked off responses to Brooks' charges.

He said that under the travel proposal, members would no longer have to justify overseas trips as being taken for business of committees to which they belong. That is a current foreign travel requirement.

Obey said that a member of the Post Office Committee should be able to go to Panama to look at the canal situation without devising "a bunk of baloney about looking at post offices in Panama . . . Everybody knows how phony the present system is."

Obey defended the proposed computer allowance that could cost the House an additional $5 million. He said the present system - which permits members to take $1,000 a month from their clerk-hire allowance - ends up taking "$12.000 out of the hides of people who work for us."

Obey concluded with a personal shot at Brooks, who also is chairman of the House Select Committee on Congressional Operaations. Obey noted Brooks had failed to mention publicly about in private: the removal of his select committee's jurisdiction over the House personnel office, which would transferred to the new administrator and supervised by the House Administration Committee!

O'Neill, in His talk before the caucus, stressed his aim to get responsibility for running the House, and the embarrassments that often go with it, off the backs of members.

"You are not elected to be housekeepers," the Speaker said, "and I want to take this responsibility away from members of Congress."

O'Neill, to illustrate his point, offhandedly remarked that House employees purchased about $750,000 worth of liquor each year for receptions held in House office buildings rooms. He used that figure to question large purchases made over-the-counter in the hodgepodge way the House is run. O'Neill said purchases "should be put out for competitive bids.

Later, he had to explain that no federal money was involved. The purchases were made for private groups and individuals for whom House reception rooms had been made available by individual members. House employees, however, supervised the catering.