> We are planning to have a subdomain under the domain assigned to us by NIC.
> Presently my domain is hcla.com but I would like to have a subdomain under
> this domain and would like to have a seperate primary name server for this
> subdomain.  For this type of setup what are the modifications required at the
> primary nameserver of hcla.com domain ie the domain assigned by NIC and
> correspondingly what are the modifications required at nameserver of the
> subdomain that we are planning to make.
 
Buy a copy of Cricket Liu's book _Managing DNS and Bind_ from
O'Reilly & Associates. You'll find all the answers you need in
there.