Rounding off of shares in case of Bonus Issue

A company wants to issue fully paid bonus shares to the existing share holders in the ratio of 2:1.  The company is having shareholders holding 25 equity shares, 75 equity shares, etc.  What is the formalities to be carried out for issue of Bonus shares with special reference to rounding of the bonus shares.  Whether we have to ignore fractions, or can we round it to the nearest digit, etc.

Please clarify referring  to the sections/standards/etc, of any

Suresh