I'm not sure I understand you. Excel with its normal custom  formats
with commas in them will divide into groups of THREE digits. The
requirement is for groups of TWO digits (except for the right-most three).
Normal Excel custom formats  (i.e. ones that insert the commas automatically)
will not do what is wanted. This is "Indian format".

skt2114, you might like to look at
www.experts-exchange.com/.../Q_20537683.html which seems to
be offering code to dynamically insert appropriate custom formats based on
cell value. This could be modified to do your Nil, if needed.

If that's not what you want, a Google search for - Indian custom format
excel - will get you lots of discussion on the subject, plus a few solutions
of various types.