What was the decision at the geneva convention?

My guess is that you mean the Geneva Conference, which was held in 1954. Representatives from the United States, the Soviet Union, the People's Republic of China, France, and Great Britain were the participants in the Geneva Conference of 1954, which addressed tensions occurring in Southeast Asia. A key problem was what to do about Vietnam. France, which had held colonial control, had been battling Vietnamese nationalist (and communist) forces led by HoChi Minh since 1946. The decision was that France would withdraw its troops from northern Vietnam, and Vietnam would be divided at the 17th parallel. This was intended as a temporary division, but conflict in Vietnam continued for decades after that in what became known as the Vietnam War.

A note about the term "Geneva Convention" ...

The term Geneva Conventions refers to specific international agreements that were made in 1949, using the term "convention" in its diplomatic sense of an international treaty agreement rather than referring to a gathering of people. The four international agreements made at that time were as follows:

The First Geneva Convention was "for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field" The Second Geneva Convention was "for the Amelioration of the Condition of Wounded, Sick and Shipwrecked Members of Armed Forces at Sea" The Third Geneva Convention was "relative to the Treatment of Prisoners of War" The Fourth Geneva Convention was "relative to the Protection of Civilian Persons in Time of War"