Wow its working...
Here are the steps to follow to park your domain from bigrock.in to your x10hosting cpanel:
Step 1: login to your x10 hosting account -> click hosting on top -> click login to cpanel -> scroll down to domains section and click parked domains -> type your domain in the space provided -> then click add domain.
Step 2 : login to bigrock.in -> place your mouse on domains and in the list appearing -> click on list all orders -> click on the domain you want to park from the table -> click on Name Servers -> over here add the name servers ns1.x10hosting.com and ns2.x10hosting.com -> click submit.
Step 3: Wait for 1-2 days for the domain to get parked.