Shall I answer Yes/No to this question?

These questions are basically statements (not grammatically questions) in a true/false format. Some questionnaires would offer True/False or T/F as the answer options.

In this case, if the statement is true, answer yes. If the statement is false, answer no.

Based on the information you have given, the answer to Question 1 is yes, and the answer to Question 2 is no.

If there is room on the form, and you want to take the time, you could write

Q1: No, I have not. (You could also say Yes, I have not, but that might be a bit confusing)

For Question 2, you would have to say

Q2: No, I have not.

As several other commentators have suggested, the questionnaire is not the most clear.

Question:

You have not attended the X company Selection Process in the last 6 months.

Answer: "Yes! I have NOT attended the X company selection process."

Question:

Have you attended the X company Selection Process in the last 6 months.

Answer: "No! i have not attended the X company process."