B.com ACS
1056 Points
Joined August 2011
He should be appointed under Section 161(4) of the Companies Act, 2013.
As rightly pointed out by learned member Mr. Pratik Shah he is considered as a retiring director and he shall hold office only up to the date up to which the director in whose place he is appointed would have held office if it had not been vacated.
Suggest you to go through the following article to get an overview on the subject
/articles/appointment-of-director-in-casual-vacancy-under-ca-2013-21913.asp