Currently the NS of domain belongs to domain registrar,could any one me :Whether I create subdomain , add domain in cpanel or any other operations,I need to add A entry in domain panel.
Why?

because it is the name server that is authoritative for the domain (that's were the records go cpanel does not have access to this )

The Hosting provider will offer you the control panel to manage domains and subdomains. Unless you point the domain to the hosting server, you won't be able to create the sub-domains.

You need DNS management with your Domain, and you need to add A entries to point the Domain to the server, and set the DNS to your own upon creation.

You need to change the DNS to the server you wish to use.

As others have said you're going to need point the domain name to your web hosting hosting/server in order to create sub-domains on your web hosting account.

Jack

Nameserver helps network to find out the place where the DNS zone is created for the domain.

Well , looking at your query since you are using the your domain registrar's default name server you will have to add the A entry of any domain or subdomain accordingly as the DNS zone of that particular domain is not hosted on your server.

If you want to avoid these things .. you need to create your own name servers, register them at your registrar , assign those name servers to your server too , this will avoid the hassle of manual addition of DNS records as you have specified

Yes, registering your own DNS is solution for you. When you will assign them in your server. Then their record will be created automatically when creating subdomain or new domain.