I am trying to create rpm of monolithic kernel.
i.e. I want disable module support.
Following steps I have performed:-
1.make xconfig --> in this i disable "Enable module support" option.
2.Now when i try to create kernel rpm using rpmbuild command.
It says enable module support and build the kernel.
3. I understood that i need to make changes in kernel.spec file.
But i am not sure where all to make changes.

Does anybody has created rpm of monolithic kernel?
Thanks in advance.

Unless there are compelling reasons for building a distributable monolithic kernel for RHEL, CentOS or Fedora that you haven't told us about (yet) I would strongly suggest you do not attempt to do that. OTOH if an exercise in futility is sorely needed, or if this is only for a local system / virtualization guest you're willing to b0rk, then you could just build and install the kernel the way you want it and then create a .spec file around those commands. Its not that hard to do really. If unsure build, install and run the kernel and list the commands you used.

I've used checkinstall to create rpms. Crude, but effective