I think you meant the following question:

a) Direction of travel at time t = 0 is in the positive direction of the axis since the value of the velocity at t = 0 is positive.

b) Direction of travel at point 4 is in the negative direction of the axis since the velocity at point 4 is negative

c) The particle reverses its direction of travel at points 3 and 5 as the velocity changes from positive to negative at point 3 and negative to positive at point 5.

d) magnitude of acceleration is given by the slope of the graph. The slope of the graph at points 1 and 4 is zero.

The slope of the graph is negative at points 2 and 3 with the slope being more negative at 2 than 3.

The slope of the graph is positive at points 5 and 6 with the slope being more positive at 6 than 5.

Therefore, the ranking is 6 > 5 > 4 = 1 > 3 > 2.