Which ocean rim is called the "ring of fire" because of the several volcanoes and other tectonic activities present there

The " ring of fire'' is called pacific ocean.

Pacific ocean because The Andes in South America, the Cascade Range of North America, and the Southern Alps of New Zealand are all associated with the Ring of Fire. The Ring of Fire is a string of volcanoes and sites of seismic activity, or earthquakes, around the edges of the Pacific Ocean.