The trustees of the University of the District of Columbia gave a sharply mixed reception yesterday to President Rafael L. Cortada's plan to create a community college within the city university.

Cortada, who urged setting up a two-year college even before he took over as university president Oct. 1, told the trustees' Educational Policy Committee that the reorganization is needed to "channel students to programs where they will have success." He said the present system of mixing two-year and four-year degree programs means that "we are not serving anyone as best we might."

"The bright students move" to other universities, Cortada said. "The poor students are not well-served either."

But trustee Daniel I. Fivel said Cortada's proposal to create a community college that takes any high school graduate and four-year programs with selective admissions might "destroy the university." Because more than 80 percent of UDC freshmen require remedial work, Fivel said, he feared that the community college would become so large that the District government might decide that it would be cheaper just to operate a community college and pay tuition for D.C. residents at the city's eight private universities.

Board Chairman N. Joyce Payne, who participated in the meeting by telephone, said Cortada had not given enough information to justify the change.

She said the president should have fit the proposal into the university's long-range master plan, and she expressed concern that it might violate the 1976 District law that authorized the university to consolidate the District's three public colleges that were existing at that time.

Cortada strongly rejected both points, and three board members -- Joseph Webb, Herbert O. Reid and Rose-Kathryn Young -- argued strongly for his plan.

"We're on the skids as far as our enrollment is concerned," said Webb, referring to UDC's loss of one-third of its enrollment in eight years.

"Extreme situations require extreme measures, and this is an extreme situation," he said.

Young said that the consolidation that created the university was "not well done . . . . Doing something is better than doing nothing and just sitting where we are now."

The UDC Faculty Senate endorsed the reorganization plan last month after extensive hearings. Since October Cortada has sent the board four draft versions of his plan, but he did not submit the formal reorganization proposal until Jan. 15.