PROVIDENCE, R.I.--About 3000 Brown University students gathered for a noon rally yesterday in support of a planned student stike at Brown next week.

The cheering crowd heard student speakers protest the Brown administration's admissions, financial aid and budgetary policy, and outline plans for a campus-wide strike vote today.

The rally was by far the biggest protest action in the Ivy League this year.

Leaders of Brown's official student government and of the ad hoc coalition coordinating strike efforts will supervise today's day-long strike ballotting.

All of Brown's 5100 undergraduates are eligible to choose between rejecting a strike completely and giving the administration until Sunday afternoon to answer the coalition's demands.

If the students choose to demand an administration response, they will vote again Monday, deciding whether to accept the response as adequate or proceed with the strike.

If the administration does not respond or if the students vote against accepting its response, the students plan to boycott classes and refuse to hand on academic work all next week.

Today's strike referendum appears likely to pass, since more than half of the Brown undergraduate body attended yesterday's rally.

Coalition leaders yesterday released a series of statistics to accompany their general demands, which include.

* An increase in nest year's undergraduate scholarship budget from the administration's $3.3 million figure to $3.5 million:

* Maintaining a black undergraduate body proportionally equal or greater in size to the number of blacks in the United States:

* Requiring that 10 per cent of the student Brown admits form the city of Providence be black and from public school:

* Requiring admissions officers to spend 20 per cent of their time "personally soliciting areas not traditionally solicited for recruitment," and.

* Maintaining present staffing levels in the University student dean's office, health services and faculty.

All of the demands are stated in terms of specific dollar budget figures, all of them slightly higher than the ones the administration has proposed for next year.