discuss Pending Delete...

It depends of tld for sure as some tld do not have 5-day pending delete.
But for you other questions i dont know...

i am also want to know about that

It would definitely change from one extension to another because each registry has its own set of zone files. VeriSign I think updates their zone files once per day (granted, we're talking about hundreds of thousands of domains) so the exact hour/minute might be hard to determine. If they are processing a list of 120,000 domains today things might take a little longer than tomorrows list which only has 90,000 (as an example).. You may want to do some more research into zone files and see how the registry works with the extension you're interested in.