You may follow the following steps to check why your website is not resolving:-
1) Please check if your domain is not expired.You may check the expiry date of your
domain from "https://secure.grabweb.net/in/domainchecker.php?search=bulkregister"
URL. If your domain is not expired then proceed further else contact grabweb sales
department to renew your domain.
2) Make sure your domain is not suspended due to overusuage of the bandwidth
and disk space.
3) If your domain is not expired and domain is not suspended then login to plesk
control panel and check if DNS is working under DNS settings. If your DNS is
switched OFF then you will get the following option on the top of the page saying
"Switch ON the DNS settings".Click on the button to start your DNS server. Please
check your website once DNS server is switched "ON".