Maximum number of Directorship eligibility

Section 275 of Companies Act states that a person holding Directorship of more than 15 companies before the commencement of Companies (Amendment) Act 2000 shall within 2 months from such commencement choose;not more than 15 companies in which he wishes to continue as director and intimate the same to registrar and Central Government.

But what if it does not chooses within this time period?

How his Directorship will be decided in that case?