Can you please check if you have an unlocked ruleset in your application? In order to be able to create new rules, you need to have an unlocked ruleset available in your application. Go through YourApplication > OpenApplication then you will be able to find the ruleset list of your Application after which you may click on UnlockAndSave button.
@Vinod, Adding to my colleague Evita's explanation, i feel like you are trying to create the new call in the PegaRULES application based on your above screenshot. So i would suggest you to create a new application then try to create the new rules in it. Hope this might help you to fix your issue.