This is the link of discussion forum for IELTS necessity for PR after Nomination.
http://www.canadavisa.com/canada-immigration-discussion-board/please-help-ielts-got-expired-during-nomination-process-at-sinp-t233955.0.html
http://www.canadavisa.com/canada-immigration-discussion-board/please-help-ielts-got-expired-during-nomination-process-at-sinp-t233955.0.html