Download iOS 9.0.1 (13A405) for iPhone 6s

You will have to note that you can only restore signed IPSW firmware files using iTunes or 3utools.

❌ This IPSW firmware is not being Signed by Apple

Firmware Identifier iPhone8,1
iOS Version 9.0.1
Release Date 2015-09-24
Update Date 2015-09-22
Sha1sum
0b61fba17b45cd99dcfed963d176238f5def1fae
Sha256sum
01694c102ac2a572afa4138e1eb552e015f7fbf474cdb8f2b8574349f169ca9c
md5sum
8c7400c2ccd355e1504001149408dad1
Size 1.99 GB
FileName
iPhone8,1_9.0.1_13A405_Restore.ipsw
Status

Download IPSW (1.99GB) Check device info
Release Notes

It should be noted that these are the official release notes for the from Apple

This update contains bug fixes including:

For information on the security content of this update, please visit this website:

http://support.apple.com/kb/HT1222