can i again download ios 7 on my phone

Sorry downgrading isn't supported by Apple.

Not to mention, since the iPhone 6 came with iOS 8, it is impossible to run a version earlier than what it came with. Even if you want to go back to 8.0, though, as razmee209 says, downgrading is not supported.

Sorry, it is not possible.

Shivam9999 wrote:

any other way if yoou can suggest that will be really apriciated

IF it isn't supported by Apple, there nothing else to suggest.

If you are experiencing a problem with your iPhone that's making you want to downgrade, tell us what that is. Since downgrading is not a solution, we can suggest something else, if you tell us what the issue is.

Shivam9999 wrote:

is there any way that i can download ios 7 on my ihone 6plus

There's no "again" involved. The iphone 6 plus NEVER had iOS 7 on it. It came with some version of iOS 8. But anyway, you cannot downgrade, even to a different point version of iOS 8.