Aoa -as per ca 2013-query

Dear all ,

Since Most of the Companies having AOA as per old Companies Act.

please suggest is there any need to adopt APPLICABLE AOA as per CA-2013 OR  we do not have to do anything??

and also suggest how far the old AOA is applicable as in so many sections it is wriiteen unless otherwise authorised by artilces.(in this case what to do and  follow)

PLS ENLIGHTEN AND HELP IN CLARIFYING THIS.