About 50 student demonstrators- using a battering ram to force open a door- broke into the office of the President of M.I.T. shortly after noon yesterday and occupied the Institute's three-room executive suite.

M.I.T. administrators and the faculty- which met for more than two and one-half hours yesterday afternoon- decided to take no immediate action to evict the demonstrators.

"We have no plan at present to move them out," Paul Gray, associate provost of the Institute, told reporters after the faculty meeting last night. "I think the group will recognize that they do not have broad support and will decide to leave."

The students- members and supporters of the school's Rosa Luxembourg chapter of SDS- were still in the executive offices as of 1:30 a.m. today.

The demonstrators, calling their action a takeover and live-in," demanded that the M.I.T. administration rescind "all past discipline" and abolish the school's student-faculty disciplinary committee.

The Institute's faculty met in emergency session yesterday afternoon to discuss responding to the two demands and to the demonstration. After more than two hours of debate, the faculty approved a resolution condemning the group's forcible entry" into the administrative offices and recommending that "appropriate disciplinary action" be taken against the demonstrators.

Gray said there was "no sentiment for calling the police" to clear the offices. The faculty debate was open to students but closed to members of the press.

The faculty's executive council has scheduled a meeting for next Tuesday to discuss disciplinary procedures, but Gray said that he thought it "unlikely" that there would be "a rehearing of the specifics" of any case.

No Plans to Talk

Gray also said that he knew of no plans to try to negotiate with the protestors.

The demonstrators occupied the university offices half-an-hour after the start of a rally called to protest the expulsion of Michael Albert- the president of M.I.T.'s. Undergraduate Association- and the placing of two other students on probation for their roles in demonstrations at M.I.T. last fall.

Moving from the cavernous lobby of M.I.T.'s Building 7 to the second floor administrative offices in Building 3, about thirty students- led by a group of four wielding a five- foot iron-pipe length forced open a little-used door to the private offices of President Howard W. Johnson.

They quickly occupied the adjoining reception area and the office of James R. Killian Jr., the chairman of the governing M.I.T. Corporation, Both Johnson and killian were out of town. Two secretaries and a receptionist left the offices voluntarily. Johnson returned in time to preside over the faculty meeting, which began at 3 p.m.

The battering ram had been specially constructed and fitted with two cross-bars to serve as handles. The persons who carried it wore ski masks over their faces and long white lab coats which concealed their clothing.

The demonstrators barred all but their supporters from the reception area and Killian's office, but allowed both press and only cockers to enter Johnson's room.

Students entered and left the occupied area frequently. Most observers at M.I.T. estimated the total number of demonstrators in the group at any one time to be about 150.

Institute spokesmen said last night that they believed that as many as half of the demonstrators were not M.I.T. students.

Albert was expelled earlier this month after the school's 12-member Disciplinary Committee found that he had disrupted an M.I.T. Alumni dinner in September and had obstructed a G. E. campus recruiter in October.

The committee- seven faculty members, three undergraduates, and two graduate students- also found him guilty of "disruptive and derisive" behavior at the committee's heading on the first two charges.