Inaugural Committee cochairman Bardyl R. Tirana is being considered for the top civil defense job in the Department of Defense, administration officials confirmed yesterday.

A White House personnel office aide said that a new director of the Civil Defense Preparedness Agency has been chosen, but that the choice will not be announced until some final background checks are completed. The aide acknowledged that Tirana was under consideration.

Tirana 39, said he has discussed the job with Defense Secretary Harold Brown and his deputy and has filled out "a pile of papers" that he submitted to the department. He said he would take the $50,000 a year if it was offered.

D.C. Civil Defense Director George Rodericks said he also has applied for the job but has not been interviewed by Defense officials.

"I am an aspirant and an applicant," Rodericks said, "I've been doing my darndest to line up support." A Florida state legislator and former county civil defense director, Frank Williams, was also told that he was being considered for the job but has not been asked to do more than submit a resume and a position paper.

The Civil Defense Preparedness Agency is a 600-employee, $82.5 million a year agency within the Defense Department. According to its spokesman, the agency's main function is to work to "alleviate the effects of an armed attack or a nuclear attack on the United States." Its current main projects is "crisis relocation planning," he said.

The director and his deputy are the only political appointees in the agency, but neither requires congressional confirmation.

Local and state civil defense professionals have in recent years been urging the appointment of a professional instead of a political appointee. It is largely for this reason that Rodericks applied for the job, he said. The state civil defense directors of Minnesota, Alabama and West Virginia also applied, Rodericks said. "Political appointees become 'good soldiers,'" Rodericks said. "They follow orders without question out of political loyalty. We need someone to stand up to the policy makers and offer real alternatives."

Rodericks has been civil defense director here for 20 years.

Tirana, a lawyer who started working on Carter's campaign coordinating transportation in November, 1975, concedes that he has no experience in civil defense. However, he said, the job involves skills in administration and communication and he has experience in both.

He is a director of a business jet corporation, a former Justice Department trial attorney, and as a lawyer in private practice has dealt with defense contracting and personnel, he said.

He served as elected member of the D.C. school board from 1970 to 1974. Last fall, before the presidential election, he was appointed inaugural committee co-chairman for Jimmy Carter's "people's inaugural."

He said that taking the defense job will mean a "substantial" pay cut, but "I've always wanted to return to government service."