if I use "use client" in my component then any component I use inside it do they automatically become client components

when your component "inside" is children then, no. If it's normally imported then, yes.

if anyone can tell how to fetch graphql data on server side

most graphql servers offer a api url that can be fetched. Put the requested schema inside the body with the variables as well and send the request to your graphql server. The response is now data that you can work with

@Karelian Bear Dog solved?

@B33fb0n3 the above issue is solved
but I have got another issue i.e the graphql caching with nextjs