Packages selection is disable
 

I am using rhel 6 when try to make image via kickstart its i am getting error message pacakages selection is disable due to downloading packages information..

Sorry but it's not very clear what your problem is, could you please add some more details? Are you trying to create a custom RHEL iso image and if so, what command are you using ?

yes i am trying to create a custom RHEL iso image with the help of kickstart..

system-config-kickstart

Ah sorry, can't say I've ever used it - I make mine by hand. Are you sure it will create an iso for you ? I thought it only created the kickstart file.