Download iOS 15.2.1 (19C63) 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 iPhone8,2
iOS Version 15.2.1
Release Date 2022-01-12
Update Date 2022-01-08
Sha1sum
2397ae4abb92fa0ae8eb8e219526ed17f764d877
Sha256sum
e87cd96a50fbffd0302bc06c54a6674500ae46ce4641499b2e72b97d2bc6d9c6
md5sum
0bf8192e3a6ae0a86e853a073e00aa68
Size 5.21 GB
FileName
iPhone_5.5_15.2.1_19C63_Restore.ipsw
Status

Download IPSW (5.21GB) Check device info
Release Notes

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

iOS 15.2.1 contains bug fixes for your iPhone including:

For information on the security content of Apple software updates, please visit this website:

https://support.apple.com/kb/HT201222