''Suicide after a nuclear war would take on a whole different context than it has in this life,'' Mr. Salzman said. The group does not condone suicide by students but he said that ''if there's going to be a nuclear war they might want to commit suicide'' and should have the option to do so.

Mr. Salzman said he originally believed that the Government should stockpile poisons for use after nuclear war but then decided that the matter was ''a health problem'' rather than a problem for government.

Mr. Salzman and Christopher Ferguson, 21, a sophomore from New Rochelle, N.Y., who is also among the organizers, said many students signed the petition to put the question on the ballot not because they supported the measure but rather ''to let it get on the ballot in the spirit of democratic process.''

In what was described as a heavy turnout, 854 students voted today. From 700 to 1,000 students usually vote in student elections, according to Beth M. Grossman, 20, a senior from New Rochelle, N.Y., who is president of Brown's undergraduate council of students. Varying Views on Measure

Students questioned today as they waited to vote seemed about evenly split on the measure.

''I don't believe in nuclear war but I don't believe in suicide pills either,'' said Diane Thiel, 17, a freshman from Miami Beach, Fla. ''It's a totally defeatist attitude - almost ridiculous.''