domains registered for each extension

[Gee]

is there any way to know how many domains registered for every extension

i use deleteddomains.com for .com .net .org
but what about the rest
and all unfamiliar extensions

 

[Mr Webname]

If you mean basic registrations then Enom interface gives a good range of domains extensions that are taken or free for a specific name, includes .co.uk, ,.cc, .com.cn etc.
If you mean for drops then I am not sure that there is much available for other extensions.