petitioner did not feel the necessity of challenging the tentative answer-key before 31.05.2016, the date specified in the notice, he cannot be precluded from challenging the same at a subsequent stage, once it is evident that the options qua question no.121 were erroneous. She further submits that it is only upon declaration of the final result that the petitioner learnt that he had not been selected on account of obtaining 0.5 marks less than the last selected candidate and, therefore, contends that his cause to challenge the answer-key arose only when he learnt that he not been selected. She submits that in any event, once it is apparent that the tentative answer-key, which was finally accepted by the respondents is on the face of it erroneous, the respondents ought to be directed to carry out the necessary correction and award additional marks to the petitioner. She finally contends that the mere delay on the part of the petitioner in seeking relief cannot be a ground to deprive him of the right to get an appointment, which he would get in case the answer key to question no.121 is corrected by the respondent.