I want to understand the concept of Sprint Release

Kishor,

As for terminology there is no such thing as a Sprint Release in Scrum and it shouldn't be more than a 'push of a button', but more often than not this is not the case. 

How long does it take for the Dev Team to release? 

Are they empowered to improve the release proces?

How often does the team deploy?

how long usually team should spend on it?

If releasing an increment into production took more than a negligible amount of time and effort, would that increment be “Done”?

It isn't necessary to "move increment on production" at the completion of a Sprint. At the completion of a Sprint, you have what the Scrum Guide refers to as a "potentially releasable Increment of "Done" product", which means that the Increment conforms to the team's (or organization's) Definition of Done.

What happens to this potentially releasable Increment of "Done" product depends on your organization. The only thing that the Scrum Guide says on the matter is that the decision to release it is the decision of the Product Owner. The Product Owner can, when there is a "Done" increment, choose to release it or not. It's also important to realize that there may be multiple "Done" increments throughout the Sprint which, at the Product Owner's discretion, may or may not be released.

What it means to release a product depends on your product and its context. It doesn't necessarily even mean release to a production environment. It may simply move to a pre-production, staging, or beta environment for more broad user access prior to being promoted to production. It may even mean making installers or source code available for the user to download and install. Your product may not even be software or may include hardware or services and your release process incorporates all of these things.

@ All thanks for your reply !

Tim - there is no term called Sprint release but i found this term on many blogs and there is huge discussion going on this so was eager to know how other team follow it.

Thomas - Our product is software products with critical features which should be available in market on time,  so whenever we plan Sprint our commitment is to meet Definition of done and move ahead with pre production release and production release, it could be release of 2-3 Sprints or 1 single Sprint..

How long does it take for the Dev Team to release? 

- Its takes 5 hours including release UAT and round of testing.

Are they empowered to improve the release proces?

- Yes we are.

How often does the team deploy?

- Deployment takes 3 hours

So i want to know how can we process this since it consumes 5-6 hours of Development team ?

It doesn't necessarily even mean release to a production environment. It may simply move to a pre-production, staging, or beta environment for more broad user access prior to being promoted to production.

I would say be conscious of the reasons for using this kind of system. If this step is necessary because of a lack of confidence in releasing to production, then additional work is required after the sprint to produce a releasable Increment.

This can have a huge impact on the transparency of what is delivered each sprint, and that might be a good reason to improve the release process, such that the team are able to gain enough confidence within the sprint.

1- Releasing into production should not take that much time. Ideally at the end of the sprint, the "Done" and usable increment should be available for everyone to see (and for acceptance of stakeholders) in a UAT enviornment. If release in production is required, then it should take a very less amount of time, ideally just a click of buttons for Product Owner. 

2- I would propose a suggestion here, if releasing in production takes more time, is it OK to add "Release the increment in Production" as a product backlog item and take it up as an item in the next sprint backlog?