If you’re Installing an Oracle Database 12.1.0.2 on Oracle Linux 6 with kernel version 2.6.32 then you’re most likely to hit this issue. I was installing it for one of the customer and the runInstaller reported one of the mandatory check as failed as shown in below screen shot:
As per the below mentioned BUG, community discussion and MOS tech note this warning can be ignored and Installation can be continued.
Bug 19287706 : 12.1.0.2 KERNEL OF PROPER VERSION IS NOT FOUND EXPECTED “2.6.39”
https://community.oracle.com/thread/3879942?start=0&tstart=0
12.1.0.2 Installation on OEL6 Fails with Error KERNEL OF PROPER VERSION IS NOT FOUND Expected = “2.6.39” (Doc ID 1924549.1)
As suggested by support in the MOS note we can simply ignore this pre-requisite condition and proceed with the Installation.
Hope helps 
regards,
X A H E E R