Defination of Subsidiary Company

According to section 4 of companies act,

a company shall, subject to the provisions of subsection (3), be deemed to be a subsidiary of another if, but only if,-
where the first-mentioned company is any other company, holds more than half in nominal value of its equity share capital;

Now what should we consider as the equity share capital...?? Issued capital, Subscribed capital or paid up cap ?