Answer: This question is pretty vague, but from how I'm thinking and interpreting the question, I'd say that the point (0,3) is a negative y-intercept.
Explanation: There's no x value so we know automatically that the point will be directly on the y axis and thus the y-intercept of a line. In cases where x is 0, whatever y is would be where the line of said point exactly crosses the y-axis. y is -3 so the line point (0,-3) belongs to would cross the y-axis at -3.
If the y value is negative, the y-intercept would overall be negative and vice versa if the y value was positive. In this case, our y is negative. In conclusion, this point is a negative y-intercept.