Hi Kaushik,
Please follow below note for update the kernel.
19466 - Downloading SAP kernel patches
Procedure:
Copy uncar files to /sapmnt/<SID>/exe, /usr/sap/<SID>/JC<nn>/exe and /SDM/exe and all application servers locations.
Rename .old to existing library files in existing kernel
For giving appropriate permissions to kernel files , logon to root user
Then run script => /sapmnt/<SID>/exe saproot.sh <SID>
Before starting the startsap , cleanipc <nr> remove
startsap
Thanks & Regards,
Balaram