We want to upgrade F5 to version 126.96.36.199, is this version has any known bug?it is stable version to install?
Best way to check is to go through the release notes , also upload the qkview to ihealth.f5.com site to check hardware/software support.
Release Note 188.8.131.52
Verify release notes https://support.f5.com/kb/en-us/products/big-ip_ltm/releasenotes/related/relnote-supplement-bigip-12-1-3-7.html. What type of modules you are using eg: LTM, APM, ASM etc...