Sub-section (6) of Section 5 provides that the articles of a company shall be in respective forms specified in Tables F, G, H, I and J in Schedule I as may be applicable to such company. Sub-section (9) of section 5 provides that nothing in this section shall apply to the articles of a company registered under any previous law unless amended under the Act.
It is not necessary, but advisable that whenever a company amends its articles, it should ensure that subsequent to the amendment, the AOA is as per the format specified under the Companies Act, 2013.
Since certain provisions of Companies Act, 2013 require specific clauses in the Articles to carry out such operations for e.g. for issuance of bonus shares, it is advisable that the Articles should be altered in line with the new requirements as various provisions themselves require specific clauses to be incorporated in the Articles.