President Carter's media adviser, Barry Jagoda, has been asked to appear on Capitol Hill tomorrow to "clarify his role in future telecommunications decisions in the Carter White House . . . and explain his future duties."

The invitation was extended yesterday by Sen. Ernest F. Hollings (D-S.C.), chairman of the communications subcommittee of the Senate Commerce, Science and Transportation Committee. The request, to appear before the full committee, apparently came in response to a letter from Sen. Barry Goldwater (R-Ariz.), a committee member.

In an April 10 letter to Hollings, Goldwater said he was "disturbed" that there was "an apparent conflict" between Jagoda's role as presidential media adviser and what Goldwater contended has been Jagoda's role as a policymaker in the area of public broadcasting.

Goldwater cited reports in the media that Jagoda had helped draft legislation for the restructuring of public broadcasting, helped select nominees for the Corporation for Public Broadcasting board of directors and reportedly influenced the content of programming aired by the Public Broadcasting Service.

Jagoda's appearance - and a White House decision on that had not been reached late yesterday pending receipt of Hollings' invitation - would be during confirmation hearings for Henry Geller to be assistant secretary of the National Administration.

Under a reorganization plan, Geller would become the official spokesman for the administration on all telecommunications policies.

In his letter to Jagoda, Hollings said that "it is my understanding that you are the president's media adviser and in no way should be involved in executive telecommunications policy or any attempts to influence it."

"However," Hollings continued, "There are reports to the contrary that have reached our attention and a clarification directly from you is in order."

As media adviser to Carter, Jagoda, 33, has had a hand in the president's fireside chats and twon meeting appearances, among other duties. He was part of the advance team on Carter's recent trip to South America and Africa.

Jagoda said yesterday that it "sounds to me like problem of misunderstanding, perhaps through our failure to make clear that I haven't been in policy matters ever since the Reorganization Plan moved the Office of Telecommunications Policy to the Commerce Department and in effect made the secretary of commerce and the assistant secretary (Geller) responsible for advising the president."

Jagoda said that as for the question of undue influence over public broadcasting, "I have long been concerned about this problem and share Sen. Goldwater's concern.

"Everything we have done at the White House in this administration has been aimed at reducing improper political influence over public broadcasting.

"I think it is absolutely improper for government officials," Jagoda continued, "to be involved in programming, particularly in the publicly-financed system of broadcasting."

In response to Goldwater's specific complaints, Jagoda said the White House personnel office had asked him for "input" when names were being solicited for the CPB nominations "because I have been in TV and know something about that field."

As for his role in shaping public broadcasting legislation, Jagoda said, "I had some input that went toward the thing Sen. Goldwater wants, less political influence on the board - specifically, adding four public members to the current 15-member board."

"I have not been involved in the public broadcasting bill for four or five months and do not plan to participate further," Jagoda added.

In addition, he said, "just to make sure there is no appearance of conflict, Rick Neustadt, who used to work for me, was shifted over to the domestic policy staff to work for Stu Eisenstadt because all the policy concerning telecommunications would come up through Commerce (under the reorganization) to Stu."

The White House aide also said he had contacted Channel 26 here to see if the public station would be interested in carrying the Feb. 26 concert by pianist Vladimir Horowitz held at the White House. But beyond insisting that first-class production personnel be used for the telecast, he said, "I had nothing to do with content."

(Sources on the Hill, yesterday said that Jagoda apparently had a major role in the selection of Geller, at one time personally interviewing the several finalists for the assistant secretaryship at the Commerce Department).

Although the Senate committee notified him Tuesday the invitation was on its way, Jagoda said he hadn't received the Hollings letter late yesterday. "Sen. Hollings is correct," he added, "that with this new structure I'm not involved in telecommunications policy and that's Geller's responsibility and I think that's healthy.

"I would hope the senators would be satisfied with a statement or affidavit and I'll be happy to write one. Needless to say, our main concern is clearing up any misunderstanding so there can be an early confirmation of Henry Geller."

Sen. Goldwater's interest in Jagoda's White House role apparently was sparked by a recent issue of The Media Report, a Washington newsletter, in which the allegations of conflict were first made.

Brian Lamb, the newsletter's published, was press aide to Clay T. Whitehead when Whitehead headed the Office of Telecommunications Policy during the Nixon administration.

At that time, White head not only advised the White House on policy matters but in a series of speeches expressed administration disapproval of network news coverage and public broadcasting program policies, a dual role which was criticized by the Democrats.