Of an estimated 11,000 students at the University of Maryland's 36,000-student College Park campus who receive some kind of financial aid, between 600 and 1,000 would be forced to drop out of school if the Reagan administration's proposed cuts in student financial aid are approved, according to estimates by university officials.

The House of Representatives recently approved the addition of $400 million to the administration's request for $900 million in student financial aid for the 1983-84 school year. The total, which will be $1.3 billion if the Senate also approves the addition, is a dramatic drop from the $3.5 billion the federal government spent on grants and aid to college students during the 1981-82 school year, before the Reagan administration began chiseling away at the student programs.

Maryland State Del. Nancy Kopp (D-Montgomery) said the state's students could lose $25 million in financial assistance next year. Kopp was one of the sponsors of state legislation passed earlier this year establishing a Maryland Higher Education Supplemental Loan Authority, which will provide loans to students.

University of Maryland students will be pressed from another direction next fall, when university fees and tuition will rise by 9 percent to a total of $1,185 for the school year. In addition, the cost of dormitory rooms will rise by 13.7 percent to $1,687, and board costs will go up by 11 percent to $1,294.

The university's director of financial aid at College Park, Ulysses Glee, said another financial indicator, the "unmet need," will rise next fall. The unmet need is the difference between the amount a student and his family can pay toward his education and the amount that can be provided in grants, loans or other types of aid. The average unmet need this year was $500, but it will go up to $900 next year, Glee said.

The financial aid director said students are being advised to seek private bank loans, and that 2,000 students had picked up the application forms for such loans during a recent three-day period.

Financial aid workers joined with the university's Student Government Association this spring to back several activities aimed at building opposition to the Reagan administration's proposed cuts in aid.

The culminating demonstration was a 10-mile walk from College Park to Capitol Hill made by about 120 students who chanted "Ronald Reagan, he's no good, send him back to Hollywood." The marchers, most wearing T-shirts that read "Finance the Future--Invest in a Student," represented the university's College Park and Baltimore campuses.

College Park campus president John Toll, one of the speakers at the send-off rally on the university campus, told the marchers, "By not training its students, America is losing its greatest resource."

At the end of their walk on Capitol Hill, the students heard Joel Packard, a representative of the National Association of State Universities and Land Grant Colleges, charge that the administration was creating myths with claims that the cuts will not affect low-income families. He said the Pell Grant, the most widely used of all federal grants, will be reduced from a maximum of $1,700 to $1,500 for an individual grant. During the 1981-82 school year, $2.279 billion in Pell Grant money was lent to 2.6 million students. The administration proposal would reduce the total to $1.4 billion to 1.8 million students. The Pell Grant funds go mainly to low-income families because eligibility is based entirely on need.

The Supplemental Educational Opportunity Grant, which provided $370 million in student aid during the 1981-82 school year and will give $278 million in 1982-83, will not be funded at all in 1983-84 under administration proposals. About 80 percent of all recipients of these funds are students from low-income families, according to Packard.