What is the terminal velocity of a 6.00-kg mass object in falling with a drag force with a magnitude that depends on speed, v, as fdrag = (30.0 n·s/m)v?

When object reached the terminal speed then its acceleration is zero

So as per Newton's II law we can say

now in that case we can say that net force is zero so here weight of the object is counter balanced by the drag force when it will reach at terminal speed

so we can write

so here we are given that

so terminal speed will be nearly 2 m/s