How to delete a community in Salesforce to maintain the limit?

Hi Pranav,

You can’t delete community from Salesforce. You can create maximum 50 communities in Salesforce. If you want to exceed your community limit then you can contact to Salesforce to do that in your org. You may also mark your community as “Inactive” so it is not counted in Active Communities. Hope it makes sense.

Thanks,
Prafull